TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
2.A.7.1:  The 4 TMS Small Multidrug Resistance (SMR) Family
*2.A.7.1.1









Small multidrug efflux pump, Smr (QacC, QacD, Ebr).  Substrates: (1) aromatic dyes (e.g., ethidium bromide), (2) quaternary amines (e.g., the disinfectant benzalkonium) and (3) derivatives of tetraphenylphosphonium (TPP) (Fuentes et al. 2005).

Bacteria
Firmicutes
Smr of Staphylococcus aureus
*2.A.7.1.2









Small multidrug efflux pump (substrates: isoniazid, tetraphenylphosphonium (TPP), erythromycin, ethidium bromide, acriflavine, safranin O and pyronin Y) (Rodrigues et al. 2013).

Bacteria
Actinobacteria
Mmr of Mycobacterium tuberculosis (P69926)
*2.A.7.1.3









Small multidrug efflux pump (substrates: cationic lipophilic drugs), EmrE. The 3-D structure of the dimeric EmrE shows opposite orientation of the two subunits in the membrane (Chen et al., 2007), and this conclusion has been confirmed (Lehner et al. 2008; Lloris-Garcerá et al. 2013). There may be a single intermediate state in which the substrate is occluded and immobile (Basting et al., 2008).  Direct interaction between substrates (TPP+ and MTP+) and Glu14 in TMS1 has been demonstrated using solid state NMR (Ong et al. 2013). A Gly90X6Gly97 motif is important for dimer formation (Elbaz et al., 2008).  Two models may account for the opposite orientations of the two identical subunits. A post-translational model posits that topology remains malleable after synthesis and becomes fixed once the dimer forms. A second, co- translational model, posits that the protein inserts in both topologies in equal proportions. Although there is topological malleability, the co-translational model may dominate under normal circumstances (Woodall et al. 2015).  Protonation of E14 leads to rotation and tilt of transmembrane helices 1-3 in conjunction with repacking of loops, conformational changes that alter the coordination of the bound substrate and modulate its access to the binding site from the lipid bilayer. The transport model that emerges from our data posits a proton-bound, but occluded, resting state. Substrate binding from the inner leaflet of the bilayer releases the protons and triggers alternating access between inward- and outward-facing conformations of the substrate-loaded transporter, thus enabling antiport without dissipation of the proton gradient (Dastvan et al. 2016). TMS4 is the known dimerization domain of EmrE (Julius et al. 2017).

The topology of helical membrane proteins is generally defined during insertion of the transmembrane helices, yet topology can change after insertion. In EmrE, topology flipping occurs so that the populations in both orientations equalize. Woodall et al. 2017 demonstrated that when EmrE is forced to insert in a distorted topology, topology flipping of the first TMS can occur, and topological malleability also extends to the C-terminal helix; even complete inversion of the entire EmrE protein can occur after the full protein is translated and inserted. Thus, topological rearrangements appear to be possible during biogenesis.

Bacteria
Proteobacteria
EmrE of E. coli
*2.A.7.1.4









Quaternary ammonium compound (cetylpyridinium, cetyldimethyl ethylammonium, hexadecyltrimethyl ammonium) efflux pump
Bacteria
Proteobacteria
SugE of E. coli (P69937)
*2.A.7.1.5









The heterooligomeric drug resistance efflux pump, YkkCD (substrates: ethidium bromide, proflavin, tetraphenylarsonium chloride, crystal violet, pyronin Y, methylviologen, cetylperdinium chloride, streptomycin, tetracycline, chloramphenicol, phosphonomycin)
Bacteria
Firmicutes
YkkCD of Bacillus subtilis
*2.A.7.1.6









The heterooligomeric drug resistance efflux pump, EbrAB (substrates: ethidium bromide, acriflavin, pyronin Y, and safranin O) (Zhang et al., 2007).
Bacteria
Firmicutes
EbrAB of Bacillus subtilis
*2.A.7.1.7









The drug resistance efflux pump, Hsmr (Ninio and Schuldiner, 2003) (exports ethidium, acriflavin tetraphenylphosphonium (TPP) and other cationic drugs).  Inhibited by a peptide with the sequence of TMS4 (Poulsen and Deber 2012). TMS4-TMS4 interactions may constitute the highest affinity locus for dimerization (Poulsen et al. 2009).

Archaea
Euryarchaeota
Hsmr of Halobacterium salinarum (B0R6K7)
*2.A.7.1.8









The putative heterodimeric SMR efflux pump, NepAB, encoded in a nicotine degradation plasmid, pAO1 (Baitsch et al., 2001; Brandsch, 2006); [probably exports methylamine; may also export excess nicotine, methylamine and/or the intermediate of nicotine catabolism, N-methyl-aminobutyrate] (Ganas et al. 2007). Uptake (Km=6μM) occurs by facilitated diffusion (Ganas and Brandsch, 2009).

Bacteria
Actinobacteria
NepAB of Arthrobacter nicotinovorans:
NepA (116 aas; Q8GAI5)
NepB (166 aas; Q8GAI6)
*2.A.7.1.9









The spermidine exporter, MdtIJ (MdtIJ = YdgEF) (Higashi et al., 2008).  Catalyzes the export of spermidine and confers resistance to deoxycholate and SDS (Nishino and Yamaguchi 2001).

Bacteria
Proteobacteria
MdtJI of E. coli
MdtJ (P69213)
MdtI (P69210)
*2.A.7.1.10









SugE Supressor of GroEL/ES (He et al., 2011). Confers resistance to cetyltrimethylammonium bromide, cetylpyridinium chloride, tetraphenylphosphonium, benzalkonium chloride, ethidium bromide, and sodium dodecyl sulfate. 

 

Bacteria
Proteobacteria
SugE of Enterobacter cloacae (D5CES3)
*2.A.7.1.11









Small MDR pump, AbeS (53% identical to EmrE of E. coli; TC# 2.A.7.1.3). Exports chloramphenicol, ciprofloxacin, erythromycin, novobiocin, acridine orange, acriflavine, benzalkonium chloride, DAPI, deoxycholate, ethidium bromide, sodium dodecyl sulfate (SDS), tetraphenylphosphonium and others (Srinivasan et al., 2009; Lytvynenko et al. 2015).  Purified AbeS binds tetraphenylphosphonium with nanomolar affinity and exhibits electrogenic transport of 1-methyl-4-phenylpyridinium after reconstitution into liposomes (Lytvynenko et al. 2016).

Bacteria
Proteobacteria
AbeS of Acinetobacter baumannii (Q2FD83)
*2.A.7.1.12









Small multidrug resistance (SMR) protein of 118 aas and 4 TMSs

Bacteria
Proteobacteria
SMR of Pseudomonas psychrotolerans
*2.A.7.1.13









Uncharacterized small multidrug resistance protein of 118 aas and 4 TMSs

Bacteria
Proteobacteria
UP of Paraburkholderia phenoliruptrix
*2.A.7.1.14









Uncharacterized protein of 123 aas and 4 TMSs

Bacteria
Proteobacteria
UP of Sorangium cellulosum (Polyangium cellulosum)
*2.A.7.1.15









SMR family protein of 116 aas and 4 TMSs

Bacteria
Actinobacteria
SMR protein of Lyngbya aestuarii
2.A.7.2:  The 5 TMS Bacterial/Archaeal Transporter (BAT) Family
*2.A.7.2.1









Hypothethical protein
Bacteria
Proteobacteria
Ycb6 of Pseudomonas denitrificans
*2.A.7.2.2









Hypothethical protein
Archaea
Euryarchaeota
Orf of Pyrococcus abyssi
*2.A.7.2.3









Uncharacterized protein of 156 aas and 5 TMSs

Eukaryota
Fungi
UP of Rhizophagus irregularis (Arbuscular mycorrhizal fungus) (Glomus intraradices)
*2.A.7.2.4









Pyridoxamine-phosphate oxidase (PNPO; N-terminal) with a C-terminal DMT family domain of 4 - 5 TMSs (Guerin et al. 2015).

Eukaryota
Fungi
PNPO of Penicillium digitatum (Green mold)
*2.A.7.2.5









Uncharacterized protein of 138 aas and 5 TMSs.

Archaea
Euryarchaeota
UP of Haloterrigena thermotolerans
*2.A.7.2.6









Uncharacterized protein of 142 aas and 5 TMSs

Bacteria
Proteobacteria
UP of Pseudomonas aeruginosa
*2.A.7.2.7









Uncharacterized protein of 137 aas and 5 TMSs.

Archaea
Euryarchaeota
UP of Natrinema versiforme
*2.A.7.2.8









Uncharacterized protein of 136 aas and 5 TMSs.

Archaea
Euryarchaeota
UP of Haloarcula vallismortis
2.A.7.3:  The 10 TMS Drug/Metabolite Exporter (DME) Family
*2.A.7.3.1









Putative acetate efflux pump, MadN (Berg et al. 1997).

Bacteria
Proteobacteria
MadN of Malonomonas rubra
*2.A.7.3.2









YdeD (EamA) efflux pump for O-acetylserine, cysteine, asparagine and glutamine (Dassler et al., 2000; Franke et al. 2003)

Bacteria
Proteobacteria
YdeD of E. coli
*2.A.7.3.3









PecM of 297 aas and 9 or 10 TMSs. Probable blue pigment (indigoidine) exporter (Rouanet and Nasser 2001).

Bacteria
Proteobacteria
PecM of Erwinia chrysanthemi
*2.A.7.3.4









YwfM
Bacteria
Firmicutes
YwfM of Bacillus subtilis
*2.A.7.3.5









Yf33
Archaea
Euryarchaeota
Yf33 of Archaeoglobus fulgidus
*2.A.7.3.6









RhtA (YbiF) Threonine/Homoserine Exporter (may export other amino acids including proline, serine, cysteine, histidine and several amino acid analogues, based on resistance phenotypes (Livshits et al., 2003))

Bacteria
Proteobacteria
RhtA (YbiF) of Escherichia coli (P0AA67)
*2.A.7.3.7









The S-adenosylmethionine uptake transporter, Sam (Tucker et al., 2003) (may function by an exchange mechanism (i.e., S-adenosyl-
methionine/S-adenosylhomocysteine exchange))
Bacteria
Proteobacteria
Sam (RPO76) of Rickettsia prowazekii
*2.A.7.3.8









10 TMS DMT superfamily member of unknown function. In an operon with glucan biosynthesis protein C and the AgnG (2.A.66.5.1) exporter. Regulated by RpiR (ribose regulator). 

Bacteria
Proteobacteria
Permease of Agrobacterium tumefaciens (A9CFB8)
*2.A.7.3.9









10 TMS DMT superfamily member of unknown function.

Bacteria
Proteobacteria
Permease of Vibriocholerae (A2P528)
*2.A.7.3.10









DUF6 domain protein of unknown function

Bacteria
Actinobacteria
DUF6 protein of Rhodococccus erythropolis (C3JHC4)
*2.A.7.3.11









Putative porter, SACE_6693, of unknown function

Bacteria
Actinobacteria
SACE_6693 of Saccharopolyspora erythraea (A4FP84)
*2.A.7.3.12









10 TMS YicL protein of 307aas; function unknown, but may export δ-levulinate or protoporphyrin IX (Kanjo et al., 2001).

Bacteria
Proteobacteria
YicL of E.coli (P31437)
*2.A.7.3.13









Putative Drug/Metabolite Exporter

Bacteria
Proteobacteria
DME of  Mannheimia haemolytica (A7JQ96)
*2.A.7.3.14









Putative Drug/Metabolite Exporter

Bacteria
Proteobacteria
DME of Comamonas testeroni (D8D9B1)
*2.A.7.3.15









Putative DUF6 protein

Bacteria
Proteobacteria
DUF6 protein of Xanthomonas vesicatoria (F0BFS6)
*2.A.7.3.16









DMT Superfamily member

Bacteria
Chlamydiae/Verrucomicrobia group
DMT member of Chlamydia trachomatis (D6YX63)
*2.A.7.3.17









Putative transporter of 10TMSs (TMSs 5-10 are possibly homologous to TMSs 1-6 in LanG (9.A.29.1.1)). LanG shows limited sequence similarity to ABC porters.

Bacteria
Chlamydiae/Verrucomicrobia group
Putative transporter of Chlamydophila abortus (Q5L5M5)
*2.A.7.3.18









DUF6 homologue, YhbE 

Bacteria
Proteobacteria
YhbE of E. coli (E1ILD8)
*2.A.7.3.19









Possible L-alanine exporter, YtfF (Hori et al., 2011).

Bacteria
Proteobacteria
YtfF of E. coli (P39314)
*2.A.7.3.20









S-adenosylmethionine/S-adenosylhomocysteine transporter (SAM/SAH transporter) (SAMHT; CTL843).  May function in SAM uptake and SAH export, perhaps by an SAM/SAH antiport mechanism (Binet et al. 2011).

Bacteria
Chlamydiae/Verrucomicrobia group
SAMHT of Chlamydia trachomatis serovar L2
*2.A.7.3.21









Putative permease of 295 aas and 10 TMSs

Bacteria
Spirochaetes
Permease of Leptospira biflexa
*2.A.7.3.22









YedA transporter of 306 aas and 10 TMSs.  Probably exports amino acids and/or other metabolites (Zakataeva et al. 2006).

Bacteria
Proteobacteria
YedA of E. coli (P0AA70)
*2.A.7.3.23









Uncharacterized transporter BU281

Bacteria
Proteobacteria
BU281 of Buchnera aphidicola subsp. Acyrthosiphon pisum
*2.A.7.3.24









Uncharacterized transporter YdeK

Bacteria
Firmicutes
YdeK of Bacillus subtilis
*2.A.7.3.25









Protein PagO

Bacteria
Proteobacteria
PagO of Salmonella typhimurium
*2.A.7.3.26









Cystine exporter, YijE, of 301 aas and 10 TMSs (Yamamoto et al. 2015).

Bacteria
Proteobacteria
YijE of Escherichia coli
*2.A.7.3.27









Uncharacterized transporter BUsg_270
Bacteria
Proteobacteria
BUsg_270 of Buchnera aphidicola subsp. Schizaphis graminum
*2.A.7.3.28









Uncharacterized transporter AF_0266
Archaea
Euryarchaeota
AF_0266 of Archaeoglobus fulgidus
*2.A.7.3.29









Uncharacterized transporter YoaV

Bacteria
Firmicutes
YoaV of Bacillus subtilis
*2.A.7.3.30









Uncharacterized transporter HI_0976.1
Bacteria
Proteobacteria
HI_0976.1 of Haemophilus influenzae
*2.A.7.3.31









Uncharacterized transporter ydeD
Bacteria
Firmicutes
YdeD of Bacillus subtilis
*2.A.7.3.32









Uncharacterized transporter YdfC

Bacteria
Firmicutes
YdfC of Bacillus subtilis
*2.A.7.3.33









DME family member

Bacteria
Actinobacteria
DME family member of Streptomyces coelicolor
*2.A.7.3.34









DME family member

Bacteria
Actinobacteria
DME family member of Streptomyces coelicolor
*2.A.7.3.35









Uncharacterized transporter YetK

Bacteria
Firmicutes
YetK of Bacillus subtilis
*2.A.7.3.36









Uncharacterized transporter AF_0510
Archaea
Euryarchaeota
AF_0510 of Archaeoglobus fulgidus
*2.A.7.3.37









The DUF6 domain transporter homologue, TrH3 (299 aas; 10 TMSs in a 2 + 8 arrangement)
Bacteria
Proteobacteria
TrH3 of Candidatus Pelagibacter ubique (Q4FKW8)
*2.A.7.3.38









Uncharacterized transporter YrdR

Bacteria
Firmicutes
YrdR of Bacillus subtilis
*2.A.7.3.39









Putative transporter

Bacteria
Actinobacteria
Putative transporter of Streptomyces coelicolor
*2.A.7.3.40









Putative transporter

Bacteria
Proteobacteria
Putative transporter of Myxococcus xanthus
*2.A.7.3.41









Hypothetical protein, HP 

Bacteria
Actinobacteria
HP of Streptomyces coelicolor (Q9AK99)
*2.A.7.3.42









Putative riboflavin porter, ImpX. Regulated by FMN riboswitch (Vitreschak et al. 2002)

Bacteria
Firmicutes
ImpX of Bacillus clausii (Q5WDG6)
*2.A.7.3.43









Uncharacterized transporter

Bacteria
Actinobacteria
Uncharacterized protein of Streptomyces coelicolor
*2.A.7.3.44









Hypothetical protein of 302 aas and 10 TMSs

Archaea
Euryarchaeota
HP of Halarcula hispanica
*2.A.7.3.45









Hypothetical protein of 363 aas and 10 TMSs

Bacteria
Planctomycetes
HP of Rhodopirellula baltica
*2.A.7.3.46









Hypothetical protein

Bacteria
Planctomycetes
HP of Rhodopirellula baltica
*2.A.7.3.47









10 TMS DME homologue of 280 aas

Archaea
Euryarchaeota
DME homologue of Pyrococcus abyssi
*2.A.7.3.48









Multidrug resistance pump, EmrE

Bacteria
Actinobacteria
EmrE of Blastococcus saxobsidens
*2.A.7.3.49









Peptidase S8 & S53 Subtilisin/kexin/sedolisin.  Has an N-terminal 10 (or 11) TMSs followed by a large hydrophilic domain that includes the protease domain. 

Bacteria
Actinobacteria
Peptidase with N-terminal 10 TMSs of Micromonospora aurantiaca
*2.A.7.3.50









Uncharacterized protein of 13 putative TMSs

Eukaryota
Bangiophyceae
Putative porter of Galdieria sulphuraria
*2.A.7.3.51









Putative permease of 494 aas

Eukaryota
Bangiophyceae
Putative permease of Cyanidioschyzon merolae
*2.A.7.3.52









Putative permease of 277 aas

Bacteria
Deinococcus-Thermus
Putative permease of Thermus oshimai
*2.A.7.3.53









Putative permease of 467 aas

Eukaryota
Bacillariophyta
Putative permease of Thalassiosira oceanica
*2.A.7.3.54









Riboflavin uptake transporter, RibN of 302 aas and 8 - 10 putative TMSs (García Angulo et al. 2013).

Bacteria
Proteobacteria
RibN of Rhizobium legumenosarum
*2.A.7.3.55









Riboflavin transporter, RibN, of 284 aas and 8 putative TMSs (García Angulo et al. 2013).

Bacteria
Proteobacteria
RibN of Ochrobactrum anthropi
*2.A.7.3.56









Riboflavin uptake porter, RibN, of 284 aas (García Angulo et al. 2013).

Bacteria
Proteobacteria
RibN of Vibrio cholerae
*2.A.7.3.57









Putative permease of 299 aas and 9 TMSs

Bacteria
Bacteroidetes/Chlorobi group
UP of Bacteroides thetaiotaomicron
*2.A.7.3.58









Possible transporter for polar amino acids including glutamate, glutamine and aspartate, DmeA. Complements a sepJ mutation in Anabaena (TC# 2.A.7.23.2) (E. Flores et al., unpublished observations)

Bacteria
Cyanobacteria
DmeA of Synechococcus elongatus (strain PCC 7942) (Anacystis nidulans R2)
*2.A.7.3.59









Uncharacterized protein of 347 aas and 10 TMSs

Bacteria
Spirochaetes
UP of Treponema denticola
*2.A.7.3.60









Uncharacterized protein of 306 aas and 10 TMSs.

Bacteria
Proteobacteria
UP of Bradyrhizobium japonicum
*2.A.7.3.61









Putative transporter, YigM, of 299 aas and 10 TMSs.

Bacteria
Proteobacteria
YigM of E. coli
*2.A.7.3.62









Uncharacterized DMT porter of 332 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Bdellovibrio exovorus
*2.A.7.3.63









Uncharacterized protein of 352 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Cupriavidus gilardii
*2.A.7.3.64









Uncharacterized protein of 304 aas and 10 TMSs

Bacteria
Spirochaetes
UP of Bdellovibrio exovorus
*2.A.7.3.65









Uncharacterized protein of 301 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Bdellovibrio exovorus
*2.A.7.3.66









Amino acid and toxic analogue exporter, YddG of 298 aas and 10 establsihed TMSs.  The 3-d x-ray structures (PD# 5I20) of this protein and a homologue (TC# 3.A.7.17.2) have been determined at 2.4 Å resolution, showing the outward facing conformation of a basket shaped structure with a central substrate binding cavity (Tsuchiya et al. 2016).

YddG of Starkeya novella, an α-proteobacterium
*2.A.7.3.67









PecM (YedA) of 294 aas and 10 TMSs.  Promotes invasion and intracellular survival of enteropathogenic E. coli (EPEC) cells (Burska and Fletcher 2014).

Bacteria
Proteobacteria
PecM of E. coli
*2.A.7.3.68









Uncharacterized protein of 303 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Methylobacterium nodulans
*2.A.7.3.69









Uncharacterized protein of 279 aas and 9 TMSs

Bacteria
Proteobacteria
UP of Methylophaga lonarensis
*2.A.7.3.70









10 TMS DMT superfamily member

Bacteria
Planctomycetes
DMT member of Rhodopirellula baltica
*2.A.7.3.71









Riboflavin uptake transporter of 299 aas and 10 TMSs, ImpX (Gutiérrez-Preciado et al. 2015). 

Bacteria
Fusobacteria
ImpX of Fusobacterium nucleatum
2.A.7.4:  The Plant Drug/Metabolite Exporter (P-DME) Family
*2.A.7.4.1









MtN21 nodulin protein
Eukaryota
Viridiplantae
MtN21 of Medicago truncatula
*2.A.7.4.2









Nodulin MfN21

Eukaryota
Viridiplantae
MfN21 of Arabidopsis thaliana (NP_173898)
*2.A.7.4.3









Nodulin MtN21/EamA-like transporter

Eukaryota
Viridiplantae
Nodulin MtN21 of Arabidopsis thaliana (Q9ZUI8)
2.A.7.5:  The Glucose/Ribose Porter (GRP) Family
*2.A.7.5.1









Glucose uptake permease, GlcU
Bacteria
Firmicutes
GlcU (GltT) of Staphylococcus xylosus
*2.A.7.5.2









Probable ribose transporter, RbsU
Bacteria
Firmicutes
RbsU of Lactobacillus sakei
*2.A.7.5.3









Glucose:H+ symporter, GlcU (YxfA) (high specificity, low affinity) (Castro et al., 2009)
Bacteria
Firmicutes
GlcU of Lactococcus lactis (Q9CDF7)
*2.A.7.5.4









Glucose permease, GlcU (also called YcxE). (Fiegler et al., 1999) (similar to 2.A.7.5.1).

Bacteria
Firmicutes
GlcU of Bacillus subtilis (P40420)
*2.A.7.5.5









The glucose uptake porter of 285 aas, GlcU (Aké et al. 2011).

Bacteria
Firmicutes
GlcU of Listeria monocytogenes
2.A.7.6:  The L-Rhamnose Transporter (RhaT) Family
*2.A.7.6.1









Rhamnose:H+ symporter, RhaT.  Belongs to the TMEM144 family in GenBank.

Bacteria
Proteobacteria
RhaT of E. coli
*2.A.7.6.2









L-rhamnose-proton symporter, RhaT, of 340 aas and 10 TMSs

Bacteria
Planctomycetes
RhaT of Rhodopirellula sallentina
*2.A.7.6.3









L-rhamnose-proton symport protein, RhaT, of 337 aas and 10 TMSs

Bacteria
Bacteroidetes
RhaT of Joostella marina
*2.A.7.6.4









Uncharacterized protein of 627 aas and 8 - 10 TMSs.

Eukaryota
Cryptophyta
UP of Guillardia theta
2.A.7.7:  The Chloramphenicol-Sensitivity Protein (RarD) Family
*2.A.7.7.1









The chloramphenicol-sensitive protein, RarD
Bacteria
Proteobacteria
RarD of Pseudomonas aeruginosa
*2.A.7.7.2









Protein RarD.  Involved in antibiotic resistance (Carruthers et al. 2010).

Bacteria
Proteobacteria
RarD of Escherichia coli
*2.A.7.7.3









Uncharacterized transporter HI_0680
Bacteria
Proteobacteria
HI_0680 of Haemophilus influenzae
2.A.7.8:  The Caenorhabditis elegans ORF (CEO) Family
*2.A.7.8.1









Hypothetical protein, Yrr6
Eukaryota
Metazoa
Yrr6 of Caenorhabditis elegans
*2.A.7.8.2









TM protein 144 homologue 2 (DUF1632 homologue).

Eukaryota
Dictyosteliida
TMP144-2 of Dictyostelium discoideum (Q54V96)
2.A.7.9:  The Triose-phosphate Transporter (TPT) Family
*2.A.7.9.1









Chloroplast triose-P/glycerate-3-P:Pi antiporter (TPT) (phosphoenolpyruvate and 2-phosphoglycerate are poor substrates).
Eukaryota
Viridiplantae
TPT of Zea mays
*2.A.7.9.2









Nongreen plastid/chloroplast glucose-P/triose-P/glycerate-P:Pi antiporter (GPT) (Both glucose-6-P and glucose-1-P are substrates; other hexose-Ps may also be transported). (Exchanges phosphoenolpyruvate for inorganic phosphate (Nozawa et al., 2007)
Eukaryota
Viridiplantae
GPT of Brassica oleracea
*2.A.7.9.3









Chloroplast phosphoenolpyruvate:Pi antiporter (PPT) (triose-Ps and glycerate- Ps are poor substrates).
Eukaryota
Viridiplantae
PPT of Zea mays
*2.A.7.9.4









Sly41p (transport function unknown)
Eukaryota
Fungi
Sly41p of Saccharomyces cerevisiae
*2.A.7.9.5









The plastidic phosphate/triosephosphate transporter, TPT (Linka et al., 2008).

Eukaryota
Bangiophyceae
TPT Galdieria sulphuraria (B5AJT1)
*2.A.7.9.6









Chloroplast Glucose-6-P/Pi antiporter-2, Gpt2

Eukaryota
Viridiplantae
Gpt2 of Arabidopsis thaliana (Q94B38)
*2.A.7.9.7









solute carrier family 35, member E2B

Eukaryota
Metazoa
SLC35E2B of Homo sapiens
*2.A.7.9.8









solute carrier family 35, member C2

Eukaryota
Metazoa
SLC35C2 of Homo sapiens (Q8VCX2)
*2.A.7.9.9









solute carrier family 35, member E1

Eukaryota
Metazoa
SLC35E1 of Homo sapiens
*2.A.7.9.10









solute carrier family 35, member E3

Eukaryota
Metazoa
member E3 of Mus musculus (Q6PGC7)
*2.A.7.9.11









The putative thiamine pyrophosphate transporter, SLC35E4

Eukaryota
Metazoa
SLC35E4 of Homo sapiens
*2.A.7.9.12









UDP-galactose, UDP-glucose and UDP-fructose transporter 2, UGAL2 (At1g76670; EamA superfamily)

Eukaryota
Viridiplantae
UGAL2 of Arabidopsis thaliana (Q9SRE4)
*2.A.7.9.13









Golgi nucleotide-sugar (probable UDP-galactose) transporter (At1g21070; EamA superfamily).

Eukaryota
Viridiplantae
At1g21070 of Arabidopsis thaliana (Q9LPU2)
*2.A.7.9.14









Putative nucleotide-sugar transporter YMD8
Eukaryota
Fungi
YMD8 of Saccharomyces cerevisiae
*2.A.7.9.15









Solute carrier family 35 member E3 (Bladder cancer-overexpressed gene 1 protein)
Eukaryota
Metazoa
SLC35E3 of Homo sapiens
*2.A.7.9.16









Solute carrier family 35 member C2 (Ovarian cancer-overexpressed gene 1 protein)
Eukaryota
Metazoa
SLC35C2 of Homo sapiens
*2.A.7.9.17









Probable sugar phosphate/phosphate translocator At2g25520
Eukaryota
Viridiplantae
At2g25520 of Arabidopsis thaliana
*2.A.7.9.18









Putative transporter C83.11
Eukaryota
Fungi
SPBC83.11 of Schizosaccharomyces pombe
*2.A.7.9.19









Glucose-6-phosphate/phosphate-translocator-like protein 1
Eukaryota
Viridiplantae
At4g03950 of Arabidopsis thaliana
*2.A.7.9.20









Golgi UDP-galactofuranose transporter, UgtA of 399 aas and 11 TMSs (Engel et al. 2009). This and several other species have two redundant transporters that can substitute for each other, UgtA and UgtB (Park et al. 2015).  Plays a role in hyphal morphogenesis, cell wall archtecture, conidiation and drug susceptibility (Engel et al. 2009). This and several other species have two redundant transporters that can substitute for each other, UgtA and UgtB (Park et al. 2015).  Plays a role in hyphal morphogenesis, cell wall archtecture, conidiation and drug susceptibility (Afroz et al. 2011).

Eukaryota
Fungi
UgtA of Aspergillus niger
*2.A.7.9.21









UDP-galactofuranose transporter of 400 aas and 11 TMSs, GlfB (Engel et al. 2009).  Galactofuranose-containing glycolipids and glycoproteins are in the cell envelopes of several eukaryotes where they have been shown to contribute, for example, to the virulence of the parasite Leishmania major and the fungus Aspergillus fumigatus.

Eukaryota
Fungi
GlfB of Neosartorya fumigata (Aspergillus fumigatus)
*2.A.7.9.22









Xylulose-5-P:Pi antiporter, Xpt or Rpt of 417 aas (Knappe et al. 2003).

Eukaryota
Viridiplantae
Xpt of Arabidopsis thaliana
*2.A.7.9.23









The triose-P:Pi antiporter, TPT or Ape2 of 410 aas. Transports inorganic phosphate, 3-phosphoglycerate (3-PGA), 2-phosphoglycerate (2PG) and phosphoenolpyruvate (PEP) as well as triose phosphates. Functions in the export of photoassimilates from chloroplasts during the day. In the light, triose phosphates are exported from the chloroplast stroma in counter exchange with inorganic phosphate (Pi), generated for sucrose biosynthesis in the cytosol. Involved in photosynthetic acclimation, a light response resulting in increased tolerance to high-intensity light (Knappe et al. 2003).

Eukaryota
Viridiplantae
TPT of Arabidopsis thaliana
*2.A.7.9.24









The phosphoenolpyruvate/phosphate translocator, pPT, of 524 aas in the outer membranes of apicoplasts, vestigial plastids in apicomplexan parasites such as Plasmodium. Transports glucose-6 P and triose-3 Ps via an inorganic phosphate antiport mechanism.  Apicomplexan parasites are dependant on their apicoplasts for synthesis of various molecules that they are unable to scavenge in sufficient quantity from their host. They import carbon, energy and reducing power to drive anabolic synthesis in the organelle. pPT is targeted into the outer apicoplast membrane via a transmembrane domain that acts as a recessed signal anchor to direct the protein into the endomembrane system. A tyrosine in the cytosolic N-terminus of the protein is essential for targeting (Lim et al. 2016).

Eukaryota
Apicomplexa
pPT of Plasmodium falciparum
2.A.7.10:  The UDP-N-Acetylglucosamine:UMP Antiporter (UAA) Family
*2.A.7.10.1









UDP-N-acetylglucosamine:UMP antiporter
Eukaryota
Fungi
Mnn2-2 of Kluyveromyces lactis
*2.A.7.10.2









The bifunctional Golgi nucleotide sugar transporter with specificity for UDP-xylose and UDP-N-acetylglucosamine, SLC35B4 (Ashikov et al., 2005).

Eukaryota
Metazoa
SLC35B4 of Homo sapiens
*2.A.7.10.3









Golgi UDP-N-acetylglucosamine (UDP-GlcNAc) transporter.

Eukaryota
Dictyosteliida
SLC35B4 (610923) of Homo sapiens (Q869W7)
*2.A.7.10.4









Endoplasmic reticular multifunctional nucleotide sugar transporter, Efr.  Substrates include GDP-fucose which can be used to fucosylate the luminar domain of the transmembrane NOTCH receptor (Ishikawa et al. 2010).

Eukaryota
Metazoa
Efr of Drosophila melanogaster
*2.A.7.10.5









ER/Golgi UDP-N-acetylglucosamine transporter, Yea4 of 342 aas.  Required for chitin biosynthesis (Roy et al. 2000).  Extracellular UDP-sugars promote cellular responses by interacting with widely distributed P2Y(14) receptors, and the ER/Golgi lumen constitutes a source of extracellular UDP-sugars (Sesma et al. 2009).  Yea4 therefore plays a critical role in nucleotide sugar-promoted cell signaling.

Eukaryota
Fungi
Yea4 of Saccharomyces cerevisiae
2.A.7.11:  The UDP-Galactose:UMP Antiporter (UGA) Family
*2.A.7.11.1









UDP-galactose:UMP antiporter.  Residues essential or important for activity have been identified (Chan et al. 2010).

Eukaryota
Metazoa
SLC35B1 of Homo sapiens
*2.A.7.11.2









Golgi adenosine 3'-phosphate 5'-phosphosulfate transporter, slalom (functions by an exchange mechanism, essential for viability (Kamiyama et al., 2003)).
Eukaryota
Metazoa
slalom of Drosophila melanogaster
(Q9VEI3)
*2.A.7.11.3









Golgi adenosine 3'-phosphate 5'-phosphosulfate (PAPS): adenosine 3'-phosphate 5'-phosphate (PAP) antiporter, PAPST1. (Mutations cause human inherited disorders (orthologue of 2.A.7.11.2) (Kamiyama et al., 2003)).
Eukaryota
Metazoa
SLC35B2 of Homo sapiens
*2.A.7.11.4









Golgi UDP-galactose/UDP-glucose:UDP antiporter, UTr1 (Norambuena et al., 2002)
Eukaryota
Viridiplantae
UTr1 of Arabidopsis thaliana
(O64503)
*2.A.7.11.5









Translocates adenosine 3'-phosphate 5'-phosphosulfate, PAPS, the high-energy sulfate donor from the cytosol to the Golgi lumen for sulfation of glycoproteins, proteoglycans and glycolipids.

Eukaryota
Metazoa
SLC35B3 of Homo sapiens
*2.A.7.11.6









UDP-galactose transporter homologue 1 (Multicopy suppressor of leflunomide-sensitivity protein 6)

Eukaryota
Fungi
HUT1 of Saccharomyces cerevisiae
*2.A.7.11.7









UDP-galactose/UDP-glucose transporter 5 (AtUTr5)
Eukaryota
Viridiplantae
UTR5 of Arabidopsis thaliana
*2.A.7.11.8









UDP-glucose transporter, UGT4.  Does not transport UDP-galactose (Seino et al. 2010).

Eukaryota
Viridiplantae
UGT4 of Oryza sativa
2.A.7.12:  The CMP-Sialate:CMP Antiporter (CSA) Family
*2.A.7.12.1









CMP-sialic acid:CMP antiporter. Amino acid residues important for CMP-sialic acid recognition have been identified (Takeshima-Futagami et al., 2012).  Residues essential for activity have been identified (Chan et al. 2010).

Eukaryota
Metazoa
CMP-sialic acid transporter of Mus musculus (Q61420)
*2.A.7.12.2









CMP-Sialic Acid Transporter (CMP-SAT)
Eukaryota
Metazoa
CMP-SAT of Aedes aegypti (Q175F9)
*2.A.7.12.3









UDP-Galactose Transporter, UTR6
Eukaryota
Viridiplantae
UTR6 of Arabidopsis thaliana (Q9C5H6)
*2.A.7.12.4









Golgi UDP-galactose and UDP-N-acetylglucosamine:UDP antiporter, SRF-3 (Hoflich et al., 2004).
Eukaryota
Metazoa
SRF-3 of Caenorhabditis elegans
(Q93890)
*2.A.7.12.5









Golgi UDP-galactose and UDP-N-acetylgalactosamine:UDP antiporter, UGT (Segawa et al., 2002)

Eukaryota
Metazoa
UGT of Drosophila melanogaster
(Q9W4W6)
*2.A.7.12.6









Golgi UDP-galactose and UDP-N-acetylgalactosamine:UDP antiporter UGT or SLC35A2 (orthologue of 2.A.7.12.5) (Segawa et al., 2002). Transports nucleotide sugars from the cytosol into Golgi vesicles where glycosyltransferases function.

Eukaryota
Metazoa
SLC35A2 of Homo sapiens
*2.A.7.12.7









Golgi UDP-N-acetylglucosamine transporter (Ishida et al., 1999a).
Eukaryota
Metazoa
SLC35A3 of Homo sapiens
*2.A.7.12.8









UDP-galactose transporter, UGT (Had-1) (Ishida et al., 1999b)
Eukaryota
Metazoa
UGT of Mus musculus (Q9R0M8)
*2.A.7.12.9









The ER/Golgi UDP-N-acetylgalactosamine (and possibly UDP-N-acetylglucosamine) transporter C03H5.2 gene product (Caffaro et al., 2006)
Eukaryota
Metazoa
C03H52 of Caenorhabditis elegans (O16658)
*2.A.7.12.10









The ZK896.9 Golgi apparatus nucleotide-sugar transporter (transports UDP-glucose, UDP-galactose, UDP-N-acetylglucosamine, and UDP-N-acetylgalactosamine) (Caffaro et al., 2008)

Eukaryota
Metazoa
ZK896.9 of Caenorhabditis elegans (O02345)
*2.A.7.12.11









Golgi CMP-sialic acid:CMP exchange transporter. Used for glycosylation within the Golgi lumen. Amino acid residues important for CMP-sialic acid recognition have been identified (Takeshima-Futagami et al., 2012).  Loss of function results in ataxia, intellectual disability, and seizures, in combination with bleeding diathesis and proteinuria (Mohamed et al. 2013).  SLC35A1 and SLC35C1, have been related to congenital disorder of glycosylation II (CDG II) (Song 2013).

Eukaryota
Metazoa
SLC35A1 of Homo sapiens
*2.A.7.12.12









Putative Golgi UDP-sugar transporter, SLC35A4. A modulatory role for SLC35A4 in intracellular trafficking of SLC35A2/SLC35A3 complexes has been proposed (Sosicka et al. 2017).

Eukaryota
Metazoa
SLC35A4 of Homo sapiens
*2.A.7.12.13









Putative nucleotide-sugar transporter, C2orf18 (371aas; 9 TMSs)

Eukaryota
Metazoa
C2orf18 of Homo sapiens (Q8N357)
*2.A.7.12.14









Probable UDP-sugar transporter protein SLC35A5 (Solute carrier family 35 member A5)
Eukaryota
Metazoa
SLC35A5 of Homo sapiens
*2.A.7.12.15









CMP-sialic acid transporter 5 (CMP-SA-Tr 5) (CMP-Sia-Tr 5)
Eukaryota
Viridiplantae
At5g65000 of Arabidopsis thaliana
*2.A.7.12.16









Pig Golgi-resident UDP-N-acetylglucosamine transporter of 325 aas and 10 TMSs with the N- and C-termini in the cytoplasm, SLC35A3.  Essential TMSs and residues have been identified (Andersen et al. 2007).

Eukaryota
Metazoa
SLC35A3 of Sus scrofa (Pig)
2.A.7.13:  The GDP-Mannose:GMP Antiporter (GMA) Family
*2.A.7.13.1









Golgi GDP-mannose:GMP antiporter, (vanadate resistance protein), VRG4 or VIG4 (Abe et al. 1999).

Eukaryota
Fungi
VRG4 of Saccharomyces cerevisiae (P40107)
*2.A.7.13.2









Golgi GDP-mannose transporter, VRG4
Eukaryota
Fungi
VRG4 of Candida albicans (Q96WN8)
*2.A.7.13.3









Golgi GDP-mannose:GDP antiporter, GONST1 (Baldwin et al., 2001).

Eukaryota
Viridiplantae
GONST1 of Arabidopsis thaliana
(Q941R4)
*2.A.7.13.4









Golgi GDP-mannose transporter, GONST2 of 375 aas (Handford et al. 2004).

Eukaryota
Viridiplantae
GONST2 of Arabidopsis thaliana
*2.A.7.13.5









Putative nucleotide sugar transporter GONST3 (Protein GOLGI NUCLEOTIDE SUGAR TRANSPORTER 3) (Handford et al. 2004).

Eukaryota
Viridiplantae
GONST3 of Arabidopsis thaliana
*2.A.7.13.6









Golgi GDP-mannose transporter of 397 aas and 10 TMSs, Gmt1.  Necessary for capsular biosynthesis, protein gycosylation and virulence (Wang et al. 2014).

Eukaryota
Fungi
Gmt1 of Cryptococcus neoformans
*2.A.7.13.7









Golgi GDP-mannose transporter, Gmt2.  Functions in capsular polysaccharide biosynthesis, protein glycosylation and virulence (Wang et al. 2014).

Eukaryota
Fungi
Gmt2 of Cryptococcus neoformans (Filobasidiella neoformans)
2.A.7.14:  The Plant Organocation Permease (POP) Family
*2.A.7.14.1









Purine/pyrimidine organocation uptake permease, AtPUP1
Eukaryota
Viridiplantae
AtPUP1 of Arabidopsis thaliana
*2.A.7.14.2









Probable purine permease 18 (AtPUP18)

Eukaryota
Viridiplantae
Pup18 of Arabidopsis thaliana
*2.A.7.14.3









Probable purine permease 11 (AtPUP11)
Eukaryota
Viridiplantae
PUP11 of Arabidopsis thaliana
*2.A.7.14.4









Purine permease 2 (AtPUP2)
Eukaryota
Viridiplantae
PUP2 of Arabidopsis thaliana
*2.A.7.14.5









Putative purine permease 15 (AtPUP15)
Eukaryota
Viridiplantae
PUP15 of Arabidopsis thaliana
2.A.7.15:  The UDP-glucuronate/UDP-N-acetylgalactosamine Transporter (UGnT) Family
*2.A.7.15.1









The Golgi UDP-N-acetylglucosamine/UDP-glucose/GDP-mannose transporter, SQV-7-like protein SQV7L, homologue of Fringe connection protein 1 (involved in Notch signalling by transporting UDP-N-acetylglucosamine) HFRC1, Slc35D1.  Transports UDP-N-acetylglucosamine (UDP-GlcNAc), UDP-glucose (UDP-Glc), and GDP-mannose (GDP-Man), with apparent Km values of 8, 2, and 0.14 μM, respectively (Suda et al. 2004).

Eukaryota
Metazoa
SLC35D2 of Homo sapiens
*2.A.7.15.2









The Golgi transporter, SQV-7. Transports UDP-glucuronic acid, UDP-N-acetylgalactosamine, and UDP-galactose (Gal). These nucleotide sugars are competitive, alternate, noncooperative substrates. Mutant sqv-7 missense alleles result in severe reductions of these three transport activities. SQV-7 did not transport CMP-sialic acid, GDP-fucose, UDP-N-acetylglucosamine, UDP-glucose, or GDP-mannose (Berninsone et al. 2001).

Eukaryota
Metazoa
SQV-7 (yk46f1.5) of Caenorhabditis elegans (Q18779)
*2.A.7.15.3









Endoplasmic reticulum (ER)/Golgi antiporter for UDP-glucuronic acid, UDP-N-acetylglucosamine and possibly UDP-xylose in exchange for UDP, Fringe connection (Frc) Essential for several signalling pathways including heparan sulfate and Fringe-dependent signalling (Selva et al. 2001).  Involved in glycosylation and processing of Notch (Goto et al. 2001).

Eukaryota
Metazoa
Frc of Drosophila melanogaster
(Q95YI5)
*2.A.7.15.4









The UDP glucuronate/UDP-N-acetylgalactosamine transporter, Slc35D1; responsible for Schneckenbecken dysplasia in humans (Hiraoka et al., 2007)

Eukaryota
Metazoa
SLC35D1 of Homo sapiens
*2.A.7.15.5









The putative Golgi UDP-sugar transporter SLC35D3 (416aas, 10 TMSs)

Eukaryota
Metazoa
SLC35D3 of Homo sapiens
2.A.7.16:  The GDP-fucose Transporter (GFT) Family
*2.A.7.16.1









The GDP-fucose transporter (GFT) (defective in human leukocyte adhesion disease II) (SLC35C1) (Zhang et al. 2012).  SLC35A1 and SLC35C1, have been related to congenital disorder of glycosylation II (CDG II) (Song 2013).

Eukaryota
Metazoa
SLC35C1 of Homo sapiens
*2.A.7.16.2









Golgi GDP-fucose-specific transporter, Gfr or CG9620 (Luhn et al., 2004).  It is required for glycan fucosylation and can also fucosylate NOTCH, a transmembrane cell fate determining receptor (Ishikawa et al. 2010).  Another transporter, the endoplasmic reticular Efr (TC# 2.A.7.10.4), can also fucoslyate NOTCH but not glycans.

Eukaryota
Metazoa
Gfr or CG9620 of Drosophila melanogaster
(Q9VHT4)
*2.A.7.16.3









Uncharacterized transporter C22F8.04
Eukaryota
Fungi
SPAC22F8.04 of Schizosaccharomyces pombe
2.A.7.17:  The Aromatic Amino Acid/Paraquat Exporter (ArAA/P-E) Family
*2.A.7.17.1









Aromatic amino acid exporter (exports Phe, Tyr, Trp, and their toxic analogues (Doroshenko et al., 2007)). Also called the paraquat (methyl viologen) exporter, YddG (also exports benzyl viologen and possibly L-alanine; Hori et al., 2011). The topology of YddG has been shown to be 10 TMSs with N- and C- termini on the inside (Airich et al., 2010).

Bacteria
Proteobacteria
YddG of Salmonella typhimurium
*2.A.7.17.2









General amino acid exporter (probably including aromatic amino acids as well as thr, met lys, glu and others), YddG.  Its topology with 10 TMSs and both the N- and C-termini inside has been established (Airich et al. 2010). This system has been used for the export of tryptophan for commercial purposes (Wang et al. 2013).  The 3-d structures (PD# 5I20) of a homologue (TC# 2.A.7.3.66) has been determined at 2.4 Å resolution, showing the outward facing conformation of a basket shaped structure with a central substrate binding cavity (Tsuchiya et al. 2016).

Bacteria
Proteobacteria
YddG of Escherichia coli
2.A.7.18:  The Choline Uptake Transporter (LicB-T) Family
*2.A.7.18.1









The high-affinity choline uptake transporter, LicB
Bacteria
Proteobacteria
LicB of Haemophilus influenzae (AAC23188)
*2.A.7.18.2









The archaeal putative permease MttP 353 aas (lMA0530) possibly a methyl amine uptake porter; D.J. Ferguson, personal communication) (10 putative TMSs)

Archaea
Euryarchaeota
MttP of Methanosarcina acetivorans (Q8TTA7)
*2.A.7.18.3









The archael putative permease MttP2 (MA0929) (possibly a methyl amine uptake porter; D.J Ferguson, personal communication). (9 putative TMSs; The N-terminal TMS may be missing).
Archaea
Euryarchaeota
MttP2 of Methanosarcina acetivorans (Q8TS76)
*2.A.7.18.4









LicB-T family member

Bacteria
Actinobacteria
LicB-T family member of Streptomyces coelicolor
2.A.7.19:  The Nucleobase Uptake Transporter (NBUT) Family
*2.A.7.19.1









Allantoin permease, UPS1 (may also transport uracil and 5-fluorouracil) (10 TMSs) (Schmidt et al., 2004)
Eukaryota
Viridiplantae
UPS1 of Phaseolus vulgaris (French bean) (AAS19930)
*2.A.7.19.2









The uptake transporter for allantoin (Km = 50 μM) and other oxo derivatives of nitrogen heterocyclic compounds, UPS1 (ureide:H+ symport permease) (10 TMSs; 5 paralogues in Arabidopsis).  Also transports purine degradation products such as uric acid and xanthine but not adenine (Desimone et al., 2002).

Eukaryota
Viridiplantae
UPS1 of Arabidopsis thaliana
(Q9ZPR7)
*2.A.7.19.3









Ureide Permease 5, UPS5 of 415 aas and 10 TMSs.  Proton-coupled transporter that transports a wide spectrum of oxo derivatives of heterocyclic nitrogen compounds, including allantoin, uric acid and xanthine, but not adenine. Mediates transport of uracil and 5-fluorouracil (a toxic uracil analog) (Schmidt et al. 2006).  Allantoin accumulation mediated by UPS5 confers salt stress tolerance (Lescano et al. 2016).

Eukaryota
Viridiplantae
2.A.7.20:  The Chloroquine Resistance Transporter (PfCRT) Family
*2.A.7.20.1









Chloroquine resistance transporter, PfCRT. Martin et al. (2009) have demonstrated Chloroquine transport via the malaria parasite's chloroquine resistance transporter. PfCRT cotransports chloroquine and Hout of the digestive vacuole (and hence away from its site of action) via a mutant form of the parasite's chloroquine resistance transporter (Lehane and Kirk, 2010).  Many mutations give rise to resistance (Tan et al. 2014).

Eukaryota
Apicomplexa
PfCRT of Plasmodium falciparum (AF495378)
*2.A.7.20.2









Crt homologue 1 (Chloroquine resistance transporter paralogue 1) (DdCRTp1)

Eukaryota
Dictyosteliida
Crtp1 of Dictyostelium discoideum
*2.A.7.20.3









Uncharacterized protein of 384 aas and 11 TMSs

Eukaryota
Viridiplantae
UP of Chlamydomonas reinhardtii (Chlamydomonas smithii)
*2.A.7.20.4









Chloroplastic chloroquine resistance transporter-1 of 447 aas and 10 TMSs, Clt-1.  Involved in thiol transport from the plastid to the cytosol. Transports both glutathione (GSH) and its precursor, gamma-glutamylcysteine (gamma-EC). Exhibits some functional redundancy with CLT3 in maintaining the root GSH pool (Maughan et al. 2010).

Eukaryota
Viridiplantae
Clt-1 of Arabidopsis thaliana (Mouse-ear cress)
2.A.7.21:  The 5 TMS Bacterial/Archaeal Transporter-2 (BAT2) Family
*2.A.7.21.1









The putative toxoflavin exporter, ToxF (co-transcribed with an RND-type toxoflavine exporter, ToxGHI; TC# 2.A.6.2.20) and reglated by a LysR transcription factor, ToxR coordinately with the toxoflavin biosynthetic enzymes  (Kim et al. 2004).

Bacteria
Proteobacteria
ToxF of Burkholderia glumae (AAV52811)
*2.A.7.21.2









Putative exporter
Bacteria
Proteobacteria
YdcZ of E. coli (P76111)
*2.A.7.21.3









Putative exporter
Archaea
Euryarchaeota
Putative exporter of Methanococcus maripaludis (CAF29821)
*2.A.7.21.4









The orotate transporter, OroP (Defoor et al., 2007) (also, transports 5-fluoroorotate)
Bacteria
Firmicutes
OroP of Lactococcus lactis (Q3SAW5)
*2.A.7.21.5









Heterodimeric SMR-like transporter with subunits of 144 and 151 aas and 4 TMSs each.  The two encoding genes map adjacent to a LysR transcription factor and on the other side, to a RhtB homologue, that possibly exports serine, threonine, homoserine and/or homoserine lactones.  Could function in the uptake of a quorum sensing acylhomoserine lactone.

Bacteria
Proteobacteria
UP of Klebsiella oxytoca
*2.A.7.21.6









Uncharacterized protein of 159 aas and 5 TMSs.

Bacteria
Deinococcus-Thermus
UP of Deinococcus maricopensis
*2.A.7.21.7









Putative transporter of 339 aas and 10 TMSs, encoded within an operon with a polyketide cyclase/dehydrase.  Possibly a polyketide exporter.

Bacteria
Actinobacteria
Transporter of Isoptericola variabilis
*2.A.7.21.8









Transporter of unknown function of 143 aas and 5 TMSs.  Its gene maps near a thioredoxin domain-containing oxidoreductase that may act on glycine, sarcosine and/or betaine.  Possibly the transporter acts on one of these substrates.

Bacteria
Firmicutes
Transporter of Clostridium acetobutylicum
*2.A.7.21.9









Putative transporter encoded within a probable operon with a ser-tRNA synthetase, serine biosynthesis enzymes, a peptidase and a MarC transporter.  May be an exporter of serine.

Bacteria
Deferribacteres
Putative serine transporter of Deferribacter desulfuricans
2.A.7.22:  The 4 TMS Small Multidrug Resistance-2 (SMR2) Family
*2.A.7.22.1









4-amino-4-deoxy-L-arabinose phosphoundecaprenol flippase, ArnEF [ArnE, 111aas; 4 TMSs; PmrL; YfbW] [ArnF, 128aas; 4 TMSs; PmrM; YfbJ] Functions in modification of lipid A during biosynthesis of lipopolysaccharide. Required for resistance to polymyxin and cationic antimicrobial peptides (Yan et al., 2007).

Bacteria
Proteobacteria
ArnEF of E. coli 
ArnE (Q47377)
ArnF (P76474) 
*2.A.7.22.2









The undecaprenyl phosphate-α-aminoarabinose flippase ArnE/ArnF heterodimer from the cytoplasm to the periplasm (Yan et al., 2007).

Bacteria
Proteobacteria
ArnEF flippase of Salmonella typhi
ArnE (P81891)
ArnF (125aas; Q8Z537)
*2.A.7.22.3









Uncharacterized protein of 130 aas and 4 TMSs

Bacteria
Spirochaetes
UP of Spirochaeta smaragdina
2.A.7.23:  The Putative Tryptophan Efflux (Trp-E) Family
*2.A.7.23.1









The putative tryptophan efflux protein, YcbK

Bacteria
Firmicutes
YcbK of Bacillus subtilis (P42243)
*2.A.7.23.2









SepJ, a novel composite protein of 751 aas needed for cellular filament integrity, proper heterocyst development and N2 fixation. It has a C-terminal DME family domain (Flores et al., 2007). Mullineaux et al. (2008) have proposed that this protein (SepJ; FraG) may be a channel-forming protein for transfer of metabolites between cells.  However, it may instead be a polar amino acid transporter since DmeA of Synecococcus (TC# 2.A.7.3.58) complements a defect in SepJ (E. Flores, unpubished observations).

Bacteria
Cyanobacteria
SepJ of Anabaena sp. PCC7120 (Q8YUK6)
2.A.7.24:  The Thiamine Pyrophosphate Transporter (TPPT) Family
*2.A.7.24.1









The mitochondrial thiamine-repressible putative thiamine pyrophosphate (TPP) transporter, Thi74 (370 aas; 10 TMSs in a 2 + 8 arrangement) (Mojzita and Hohmann, 2006)
Eukaryota
Fungi
Thi74 of Saccharomyces cerevisiae
(Q04083)
*2.A.7.24.2









The DUF6-domain transporter homologue, TrH1
Eukaryota
Dictyosteliida
TrH1 of Dictyostelium discoideum (Q54E05)
*2.A.7.24.3









The DUF6-domain transporter homologue, TrH2 (392 aas; 10 TMSs in a 2 + 4 + 4 arrangement)
Eukaryota
Metazoa
TrH2 of Caenorhabditis elegans (Q95XC7)
*2.A.7.24.4









The At3g07080 DUF6 domain transporter homologue
Eukaryota
Viridiplantae
At3g07080 of Arabidopsis thaliana (Q9SFT8)
*2.A.7.24.5









Uncharacterized vacuolar membrane protein YML018C
Eukaryota
Fungi
YML018C of Saccharomyces cerevisiae
*2.A.7.24.6









The DUF6-domain-containing solute carrier family 35, member F5 (523 aas; 10 TMSs, 2 + 4 + 4)
Eukaryota
Metazoa
SLC35F5 of Homo sapiens
*2.A.7.24.7









DUF6 domain-containing protein with 150aa N-terminal hydrophilic extension

Eukaryota
Fungi
DUF6 protein of Trichophyton equinum (F2PXJ5)
*2.A.7.24.8









The thiamin uptake transporter, SLC35F3. Involved in hypertension.

Eukaryota
Metazoa
SLC35F3 of Homo sapiens
*2.A.7.24.9









SLC family 35 member F1 (SLC35F1; also called DUF914)

Eukaryota
Metazoa
SLC35F1 of Homo sapiens
*2.A.7.24.10









SLC family 35 member F2 (SLC35F2; also called DUF914)

Eukaryota
Metazoa
SLC35F2 of Homo sapiens
*2.A.7.24.11









SLC family 35 member F2 (SLC35F2; also called DUF914)

Eukaryota
Fungi
SLC35F2 of Aspergillus fumigatus
(Q4WUA9)
*2.A.7.24.12









DUF914 protein, possibly anthocyanin-related protein-1 (Anm1)

Eukaryota
Viridiplantae
DUF914 protein of Arabidopsis thaliana (Q948Q9)
*2.A.7.24.13









Protein of unknown function (claimed to have extra cytoplasmic N- and C-termini (Västermark et al., 2011)). The 10 TMSs occur in a 6+4 arrangement.

Eukaryota
Kinetoplastida
Unknown protein of Trypanosoma brucei (Q57UU3)
*2.A.7.24.14









Solute carrier family 35 member F4
Eukaryota
Metazoa
SLC35F4 of Homo sapiens
*2.A.7.24.15









Uncharacterized DMT superfamily homologue

Eukaryota
Fungi
Uncharacterized protein of Lodderomyces elongisporus
2.A.7.25:  The NIPA Mg2+ Uptake Permease (NIPA) Family
*2.A.7.25.1









The nonimprinted in Prader-Willi/Angelman syndrome, subtype 1, NIPA1 Mg2+ uptake permease (329aas; 9TMSs) (Quamme, 2009)

Eukaryota
Metazoa
NIPA of Homo sapiens (Q7RTP0)
*2.A.7.25.2









The nonimprinted in Prader-Willi/Angelman syndrom, subtype 2, NIPA2 protein (360 aas; 9TMSs, 43% identical with NIPA1) Mg2+ transport is electrogenic, voltage dependent, and saturable, a KM of 0.31mM (very selective for Mg2+). (Goytain et al. 2008)

Eukaryota
Metazoa
NIPA2 of Homo sapiens (Q8N8Q9)
*2.A.7.25.3









NIPA3 protein (406 aas)
Eukaryota
Metazoa
NIPA3 of Homo sapiens (Q6P499)
*2.A.7.25.4









The ichthyin (ICHN) autosomal recessive congenital ichthyosis (ARCI) disease protein (404 aas; 9TMSs)

Eukaryota
Metazoa
ICHN of Homo sapiens (Q0D2K0)
*2.A.7.25.5









The permease-related protein (PRP) (335 aas; 9TMSs)
Eukaryota
Viridiplantae
PRP of Arabidopsis thaliana (Q9LIR9)
*2.A.7.25.6









Hypothetical protein (HP)
Eukaryota
Fungi
HP of Neurospora crassa (Q7RWT8)
*2.A.7.25.7









Protein AN62992 (691 aas; 9TMSs at the N-terminus (1-300 aas)). The C-terminal region (DUF803) is very hydrophobic.
Eukaryota
Fungi
AN62992 of Aspergillus nidulans (Q5AZI1)
*2.A.7.25.9









Magnesium transporter NIPA3 (NIPA-like protein 1) (Non-imprinted in Prader-Willi/Angelman syndrome region protein 3 homologue)

Eukaryota
Metazoa
Nipal1 of Mus musculus
2.A.7.26:  The 2 or 4 TMS Small Multidrug Resistance-3 (SMR3) Family

YnfA is a 108 aa E. coli protein with 4 established TMSs and both the N- and C-termini in the periplasm (Drew et al., 2002). Its homologues are found in a broad range of Gram-negative and Gram-positive bacteria as well as archaea and eukaryotes. The sizes of bacterial homologues range from 98 aas to 132 aas, with a few exceptions. Plant proteins can be as large as 197aas. The first two TMSs are homologous to the second two in these 4 TMS proteins. A Methanosarciniae mazei homologue of 94 aas and a Geobacillus kaustophilus homologue of 104 aas have only 2 TMSs with 30 residue extensions C- and N-terminal, respectively. No functional data are available for any of its homologues. This family is the YnfA UPF0060 family.

*2.A.7.26.1









YnfA of 108 aas and 4 TMSs. YnfA increases the antibiotics' resistance of E. coli strains isolated from the urinary tract, and is an SMR-like drug efflux pump (Sarkar et al. 2015).

Bacteria
Proteobacteria
YnfA of E. coli
*2.A.7.26.2









MA_3936 (4 TMSs)

Archaea
Euryarchaeota
MA_3936 of Methanosarcina acetivorans (gi#19918023)
*2.A.7.26.3









Sitka Spruce 4 TMS YnfA family homologue (144aas).

Eukaryota
Viridiplantae
YnfA homologue of Picea sitchensis (ADE77612)
*2.A.7.26.4









Moss 4-5 TMS YnfA family homologue (197aas)

Eukaryota
Viridiplantae
YnfA homologue of Physcomitrella patens (A9T501)
*2.A.7.26.5









Hypothetical protein, GK2092 (2 TMSs)

Bacteria
Firmicutes
GK2092 of Geobacillus kaustophilus (Q5KY59)
*2.A.7.26.6









MM_0735 (2 TMSs)

 

Archaea
Euryarchaeota
MM_0735 of Methanosarcina mazei (Q8PYW4)
2.A.7.27:  The Ca2+ Homeostasis Protein (Csg2) Family
*2.A.7.27.1









Csg2 (Cls2) Ca2+ homeostasis protein. Cells lacking Csg2p accumulate Ca2+ in a pool which is exchangeable with extracellular Ca2+ . The mutant cells are Ca2+ sensitive. The protein has 410 amino acyl residues, with 9-10 TMSs. It exhibits an EF-hand Ca2+ binding motif on the lumenal side of the endoplasmic reticular membrane. It is possible that it functions in Ca2+ sequestration. It regulates the activities of CSH1 and SUR1 during mannosyl phosphorylinositol ceramid synthesis. It forms heterodimers with CSH1 and SUR1 (Beeler et al. 1994; Takita et al. 1995). Cls2p likely functions in releasing Ca2+ from the endoplasmic reticulum, somehow cooperating with calcineurin (Tanida et al. 1996). It regulates the transport and protein leves of the inositol phosphorlyceramide mannosyltransferases Csg1 and Csh1 (Uemura et al. 2007).

Eukaryota
Fungi
Csg2 of Saccharomyces cerevisiae (P35206)
2.A.7.28:  The Solute Carrier 35G (SLC35G) Family
*2.A.7.28.1









Solute carrier family 35 member G1

Eukaryota
Metazoa
SLC35G1 of Homo sapiens (Q8BY79)
*2.A.7.28.2









Solute carrier family 35 member G2

Eukaryota
Metazoa
SLC35G2 of Homo sapiens
*2.A.7.28.3









Solute carrier family 35 member G3

Eukaryota
Metazoa
SLC35G3 of Homo sapiens (Q5F297)
*2.A.7.28.4









Solute carrier family 35 member G4

Eukaryota
Metazoa
SLC35G4 of Homo sapiens
*2.A.7.28.5









Solute carrier family 35 member G5

Eukaryota
Metazoa
SLC35G5 of Homo sapiens
*2.A.7.28.6









Solute carrier family 35 member G6

Eukaryota
Metazoa
SLC35G6 of Homo sapiens
*2.A.7.28.7









Solute carrier family 35 member G3 (Acyl-malonyl-condensing enzyme 1) (Transmembrane protein 21A)
Eukaryota
Metazoa
SLC35G3 of Homo sapiens
*2.A.7.28.8









Solute carrier family 35 member G1 (Transmembrane protein 20)
Eukaryota
Metazoa
SLC35G1 of Homo sapiens
*2.A.7.28.9









Uncharacterized transporter HP_1234
Bacteria
Proteobacteria
HP_1234 of Helicobacter pylori
*2.A.7.28.10









Uncharacterized protein of 340 aas and 10 TMSs

Eukaryota
Florideophyceae
UP of Chondrus crispus (Carragheen moss) (Irish moss)
*2.A.7.28.11









Uncharacterized protein of 304 aas and 10 TMSs.

Bacteria
Cyanobacteria
UP of Prochlorococcus marinus
2.A.7.29:  The Uncharacterized DMT-1 (U-DMT1) Family
*2.A.7.29.1









Uncharacterized DUF803 protein of 814 aas and 10 TMSs.

Eukaryota
Apicomplexa
UP of Toxoplasma gondii
*2.A.7.29.2









Uncharacterized protein of 483 aas and 10 TMSs.  May have magnesium transport activity.

Eukaryota
Apicomplexa
UP of Plasmodium falciparum
*2.A.7.29.3









Uncharacterized protein of 470 aas and 9 or 10 TMSs.

Eukaryota
Oomycetes
UP of Pythium ultimum
*2.A.7.29.4









Probable Mg2+ transporter. May also transport other divalent cations such as Fe2+, Sr2+, Ba2+, Mn2+ and Co2+ but to a much lesser extent than Mg2+.

Eukaryota
Viridiplantae
Putative Mg2+ transporter of Glycine max (Soybean) (Glycine hispida)
2.A.7.30:  The Uncharacterized DMT-2 (U-DMT2) Family
*2.A.7.30.1









Hypothetical protein of 299 aas and 10 putative TMSs

Bacteria
Planctomycetes
HP of Rhodopirellula baltica
*2.A.7.30.2









Uncharacterized putative permease of 295 aas and 10 TMSs.

Bacteria
Bacteroidetes
UP of Flavobacterium frigoris
2.A.7.31:  The Uncharacterized DMT-3 (U-DMT3) Family
*2.A.7.31.1









10 TMS DMT Superfamily member

Bacteria
Proteobacteria
DMT protein of Myxococcus xanthus (Q1DCP3)
*2.A.7.31.2









10 TMS DMT Superfamily member

Bacteria
Proteobacteria
Legionella pneumophila (A5IFT5)
*2.A.7.31.3









10 TMS DMT Superfamily member

Bacteria
Proteobacteria
DMT protein of Rhizobium torpici (L0LHM3)
2.A.7.32:  The Uncharacterized DMT-4 (U-DMT4) Family
*2.A.7.32.1









The transmembrane protein TMEM234 of 164 aas and 4 TMSs.

Eukaryota
Metazoa
TMEM234 of Homo sapiens
*2.A.7.32.2









TMEM234 of 127 aas and 4 TMSs.

Eukaryota
Metazoa
TMEM234 of Caenorhabditis elegans
*2.A.7.32.3









Uncharacterized protein of 128 aas.

Eukaryota
Dictyosteliida
UP of Dictyostelium discoideum
*2.A.7.32.4









Uncharcterized protein of 182 aas and 4 TMSs

Eukaryota
Fungi
UP of Pyrenophora teres
*2.A.7.32.5









Uncharacterized protein of 121 aas

Eukaryota
Kinetoplastida
UP of Leishmania infantum
2.A.7.33:  The Uncharacterized DMT-5 (U-DMT5) Family

Most closely related to the SMR2 Family (2.A.7.22).

*2.A.7.33.1









Permease of 116 aa

Bacteria
Fibrobacteres/Acidobacteria group
Permease of Solibacter usitatus
*2.A.7.33.2









Uncharacterized protein of 116 aas.

Bacteria
Bacteroidetes/Chlorobi group
UP of Bacteroides fragilis
*2.A.7.33.3









Uncharacterized protein of 123 aas.

Bacteria
Proteobacteria
UP of Burkholderia caribensis
*2.A.7.33.4









EmaA-like transporter of 111 aas.

Bacteria
Cyanobacteria
UP of Dactylococcopsis salina
*2.A.7.33.5









Uncharacterized protein of 116 aas

Bacteria
Actinobacteria
UP of Olsenilla profusa
*2.A.7.33.6









Uncharacterized protein of 114 aas and 4 TMSs

Bacteria
Firmicutes
UP of Thermincola potens
*2.A.7.33.7









SMR protein of 127 aas and 4 TMSs

Bacteria
Cyanobacteria
SMR protein of Nostoc punctiforme
2.A.7.34:  The Uncharacterized DMT-6 (U-DMT6) Family
*2.A.7.34.1









DUF486 transporter of 113 aas and 4 TMSs.

Bacteria
Proteobacteria
UP of Laribacter hongknogensis
*2.A.7.34.2









DUF486 transporter of 117 aas and 4 TMSs.

Bacteria
Proteobacteria
UP of Xanthomonas campestris
*2.A.7.34.3









DUF486 homologue of 122 aas

Bacteria
Bacteroidetes/Chlorobi group
UP of Bacteroides fragilis
*2.A.7.34.4









DUF486 homologue of 112 aas

Archaea
Euryarchaeota
UP of Methanococcus maripaludis
*2.A.7.34.5









DUF486 homologue of 124 aas

Bacteria
Bacteroidetes/Chlorobi group
UP of Cytophaga hutchinsonii
*2.A.7.34.6









DUF486 homologue of 122 aas

Bacteria
Spirochaetes
UP of Brachyspira intermedia
*2.A.7.34.7









Small multidrug resistance (SMR) protein of 116 aas

Bacteria
Fibrobacteres/Acidobacteria group
SMR protein of Terriglobus saanensis
*2.A.7.34.8









Uncharacterized protein of 179 aas

Eukaryota
Isochrysidales
UP of Emiliania huxleyi
*2.A.7.34.9









Uncharacterized protein of 146 aas

Eukaryota
Cryptophyta
UP of Guillardia theta
2.A.7.35:  The Uncharacterized DMT-7 (U-DMT7) Family
*2.A.7.35.1









Membrane protein

Bacteria
Actinobacteria
Membrane protein of Corynebacterium matruchotii (E0DBX6)
*2.A.7.35.2









NIPA family member

Bacteria
Actinobacteria
NIPA family member of Streptomyces coelicolor
*2.A.7.35.3









Uncharacterized permease of 370 aas

Bacteria
Actinobacteria
UP of Frankia sp.
*2.A.7.35.4









Uncharacterized protein of 311 aas and 9 TMSs

Bacteria
Actinobacteria
UP of Kribbella flavida
*2.A.7.35.5









Uncharacterized protein of 292 aas and 9 TMSs

Bacteria
Actinobacteria
UP of Streptomyces grisius
*2.A.7.35.6









Uncharacterized protein of 299 aas and 8 TMSs

Bacteria
Actinobacteria
UP of Streptomyces coelicolor
*2.A.7.35.7









Uncharacterized protein of 295 aas

Bacteria
Actinobacteria
UP of Conexibacter woesei
*2.A.7.35.8









Uncharacterized protein of 289 aas

Bacteria
Actinobacteria
UP of Amycolatopsis mediterranei
*2.A.7.35.9









Uncharacterized protein of 303 aas and 9 TMSs

Bacteria
Actinobacteria
UP of Thermobifida fusca
*2.A.7.36.1









EamA-like transporter of 287 aas and 10 TMSs

Bacteria
Actinobacteria
EamA-like protein of Mycobacterium chubuense
*2.A.7.36.2









Uncharacterized protein of 283 aas and 10 TMSs

Bacteria
Actinobacteria
UP of Acidothermus cellulolyticus
*2.A.7.36.3









Uncharacterized protein of 275 aas and 10 TMSs

Bacteria
Actinobacteria
UP of Geodermatophilus obscurus
*2.A.7.36.4









Uncharacterized protein of 291 aas and 10 TMSs

Bacteria
Deinococcus-Thermus
UP of Truepera radiovictrix
*2.A.7.36.5









Uncharacterized protein of 281 aas and 10 TMSs

Archaea
Euryarchaeota
UP of Methanolobus psychrophilus
*2.A.7.37.1









Uncharacterized protein of 164 aas and 4 TMSs.

Bacteria
Proteobacteria
UP of Delftia acidovorans
*2.A.7.37.2









Uncharacterized protein of 132 aas and 4 TMSs.

Bacteria
Proteobacteria
UP of Pseudomonas chlororaphis subsp. aureofaciens
*2.A.7.37.3









Uncharacterized protein of 139 aas and 4 TMSs.

Bacteria
Proteobacteria
UP of Rhizobium mesoamericanum
*2.A.7.38.1









Uncharacterized protein of 301 aas and 10 or fewer TMSs.

Bacteria
Proteobacteria
UP of Parvibaculum lavamentivorans
*2.A.7.38.2









Uncharacterized protein of 343 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Agrobacterium radiobacter
*2.A.7.38.3









Uncharacterized protein of 298 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Maritimibacter alkaliphilus
*2.A.7.40.1









Uncharacterized protein of 292 aas and 10 TMSs.

Bacteria
Proteobacteria
UP of Desulfobacca acetoxidans
*2.A.7.40.2









Uncharacterized protein of 297 aas and 10 TMSs

Bacteria
Bacteroidetes
UP of Fibrisoma limi
*2.A.7.40.3









Uncharacterized protein of 324 aas and 10 TMSs

Bacteria
Proteobacteria
UP of Methylotenera versatilis