2.A.115 The Novobiocin Exporter (NbcE) Family
The NbcE (formerly the YitT (DUF161)) family consists mostly of 6 TMS proteins, where these TMSs are frequently in a 2 2 2 arrangement. However, distant 5 and 3 TMS proteins may be members of this family. Several homologues are annotated as exporters or efflux transporters. The 3-d structure (PDB# 3HLU_A) is available for YitT of Bacillus subtilis. This protein has a DUF161-DUF161-DUF2179 domain arrangement according to CDD. Most homologues are from bacteria with a preponderance from firmicutes, but others are found in more distantly related organisms. One homologue, NbcE of Lactobacillus brevis, has been shown to be a novobiocin exporter (TC# 2.A.115.2.4). It has 195 aas and 4 or 5 TMSs (Pagliai et al. 2010).
The YitT (UPF0750) efflux transporter. 3-d structure known (PDB# 3HLU_A).
YitT of Bacillus subtilis (P39803)
The YxkD (UPF0750) membrane protein
YxkD of Bacillus subtilis (P94357)
The Hypothetical Protein, HP. 6 TMSs in a 2+2+2 arrangement.
HP of Rhizobium etli (Q2KCS0)
DUF161 protein of unknown function (6 TMSs in a 2+2+2 arrangement).
DUF161 protein of Brucella sp. NF 2653 (E0DTC9)
Hypothetical protein of 289 aas
HP of Desulfohalobium retbaense
DUF2179 protein of unknown function (3 TMSs)
DUF2179 protein of Mestoga prima (E0HYB9)
3 TMS protein
3 TMS protein of Methanoregula boonei (A7I6E8)
DUF2179 protein of 196 aas
DUF2179 protein of Petrotoga mobilis
The 5 TMS YczE protein. May be distantly related to CirC (5TMSs; 9.B.98.1.4).
YczE of Bacillus subtilis (E0U2C9)
Uncharacterized protein of 215 aas
UP of Methanocorpusculum labreanum
Hypothetical 6 TMS protein, HP
HP of Haloplasma contractile (F7PTN4)
Uncharacterized protein of 212 aas
UP of Faecalibacterium prausnitzii
Uncharacterized protein of 205 aas
UP of Clostridium difficile
Fusion protein of DUF161 membrane domain of 6 TMSs with a cytidylate kinase 2 domain; 428 aas
Fusion protein of Slackia heliotrinireducens
Uncharacterized protein of 222 aas
UP of Deinococcus radiodurans
The 5 TMS YyaS protein
YyaS of Bacillus pseudofirmus (D3FUL0)
The 5 TMS membrane protein, 5-MP
5-MP of Enterococcus faecalis (F2MS25)
Novobiocin exporter, NbcE, of 195 aas and 4 or 5 TMSs (Pagliai et al. 2010).
Novobiocin exporter of Lactobacillus brevis
COG2364 homologue of 221 aas
COG2364 homologue of Bacillus cereus
Hypothetical protein of 238 aas
HP of Kytococcus sedentarius
Hypotheitical protein of 224 aas
HP of Thermobifida fusca
Hypothetical protein of 222 aas
HP of Brachyspira hyodysenteriae
Uncharacterized protein of 238 aas
UP of Eubacterium eligens