TCDB » SEARCH

TCID	Name	Domain	Kingdom/Phylum	Protein(s)
9.A.8.1.1	Ferrous iron uptake system, FeoAB. FeoB is the main transporter while FeoC is a transcriptional regulator. FeoA has a Src-Homology (SH3) domain (a β-barrel with two overlying α-helices) plus two extra α-helices not usually found in SH3 domains. FeoA interacts with the cytoplasmic domain of the conserved core portion of the FeoB transmembrane region, but may not function as a GTPase activator as previously proposed (Lau et al. 2012). FeoB transports Fe(II) from the periplasm to the cytoplasm, but the C-terminal domain can also bind Mn²⁺ and Zn²⁺ as well (Orzel et al. 2023).	Bacteria	Pseudomonadota	FeoAB of E. coli FeoA (P0AEL3) FeoB (P33650)
9.A.8.1.2	Ferrous iron uptake system	Bacteria	Campylobacterota	FeoB of Helicobacter pylori
9.A.8.1.3	Ferrous iron uptake system	Bacteria	Cyanobacteriota	FeoB (slr1392) of Synechocystis PCC6803
9.A.8.1.4	Ferrous iron uptake system, FeoB (Louvel et al., 2005)	Bacteria	Spirochaetota	FeoB of Leptospira biflexa (AAU93398)
9.A.8.1.5	Ferrous iron (Fe²⁺) uptake system, FeoB1 (Dashper et al., 2005)	Bacteria	Bacteroidota	FeoB1 of Porphyromonas gingivalis (AAQ66162)
9.A.8.1.6	Manganous ion (Mn²⁺) uptake system, FeoB2 (Dashper et al., 2005)	Bacteria	Bacteroidota	FeoB2 of Porphyromonas gingivalis (AAQ66370)
9.A.8.1.7	FeoAB of 704 and 84 aas, respectively (Uebe and Schüler 2016).	Bacteria	Pseudomonadota	FeoAB of Magnetospirillum gryphiswaldense
9.A.8.1.8	The putative Fe²⁺ transport protein B, FeoB (COG3366 family)	Archaea	Euryarchaeota	FeoB of Archaeoglobus fulgidus (O29993)
9.A.8.1.9	Ferrous iron transport protein B homolog	Archaea	Euryarchaeota	MJ0566 of Methanocaldococcus jannaschii
9.A.8.1.10	FeoABC Fe²⁺ transporter (Hung et al., 2012). FeoA is a 75 aa protein homologous to the N-terminus of FeoB2 of Porphyromonas gingivalis (TC#9.A.8.1.6) and with some sequence similarity to an internal hydrophilic segment of the RND heavy metal porter, CzcA of Myxococcus xanthus (TC#2.A.6.1.7). Linkous et al. 2019 have determined the crystal structure of FeoA from Klebsiella pneumoniae (KpFeoA). The structure reveals an SH3-like domain that mediates interactions between neighboring polypeptides via hydrophobic intercalations into a Leu-rich surface ridge. Using docking of a small peptide corresponding to a postulated FeoB partner binding site, they demonstrated that KpFeoA can assume both "open" and "closed" conformations, controlled by binding at this Leu-rich ridge. They propose a model in which a "C-shaped" clamp along the FeoA surface mediates interactions with its partner protein, FeoB (Linkous et al. 2019).	Bacteria	Pseudomonadota	FeoABC of Klebsiella pneumoniae FeoA (B5XTS8) FeoB (B5XTS7) FeoC (B5XTS6)
9.A.8.1.11	FeoB of 595 aas. The structure of the N-terminal GTPase domain has been determined by NMR (Deshpande et al. 2013). GTP hydrolysis has been reported to be required for transport activity.	Bacteria	Pseudomonadota	FeoB of Gallionella capsiferriformans (strain ES-2) (Gallionella ferruginea capsiferriformans (strain ES-2))
9.A.8.1.12	Iron transporter, FeoB, of 751 aas and 9 putative TMSs with a C-terminal GTPase domain. Plays a key role in iron uptake and virulence. The crystal structure of the N-terminal cytosolic domain (NFeoB) is known (Petermann et al. 2010). The strucuture reveals a monomeric protein comprised of two separate sub-domains with GTPase and guanine-nucleotide dissociation inhibitor (GDI) functions, respectively. The GDI domain was found to display a novel fold, whereas the GTPase domain resembled that of known G domains. The crystalized protein was in the rarely observed nucleotide-free state.	Bacteria	Pseudomonadota	FeoB of Legionella pneumophila, the causative agent of Legionnaires' disease
9.A.8.1.13	FepB of 827 aas and 9 TMSs. Fe²⁺ uptake system, probably driven by GTP (Veeranagouda et al. 2014).	Bacteria	Bacteroidota	FeoB of Bacteroides fragilis
9.A.8.1.14	Ferrous iron ion uptake transporter of 669 aas and 10 TMSs in a 5 + 5 arrangement (C-terminal, with an N-terminal GTPase). Under anaerobic conditions FeoB is the major protein required for the uptake of iron into the cell and that it may play an important role in the C. perfringens pathogenesis (Awad et al. 2016).	Bacteria	Bacillota	FeoB of Clostridium perfringens
9.A.8.1.15	FeoB of 766 aas and 10 TMSs, a potential GTP hydrolysis-driven active transporter or GTP-activated iron uptake channel. The membrane domain of the trimeric FeoB forms a central pore lined by highly conserved cysteine residues. This pore aligns with a central pore in the N-terminal GTPase domain (G-domain) which is lined by aspartyl residues. Biochemical analyses revealed a putative iron sensor domain that could connect GTP binding/hydrolysis to the opening of the pore. Thus, FeoB may be a GTP-gated channel or GTP hydrolysis-driven primary active transporter (Seyedmohammad et al. 2016).	Bacteria	Pseudomonadota	FeoB of Pseudomonas aeruginosa
9.A.8.1.16	FeoA2/B2 of 78 and 788 aas, respectively.	Bacteria	Pseudomonadota	FeoA2B2 of Magnetospirillum gryphiswaldense MSR-1 v2
9.A.8.1.17	Putative FeoB homologue of 440 aas and 11 TMSs in a 3 + 3 + 5 TMS arrangement. It may function with a putative GTP-binding protein EngB. This proposed system is lacking a five-helix helical domain, which however, other proteins in this family also lack.	Archaea	Candidatus Thorarchaeota	FeoB homologue + GTPase of Candidatus Thorarchaeota archaeon
9.A.8.1.18	FeoABC ferrous iron (Fe²⁺) uptake system. All three subunits are required for activity (Gómez-Garzón et al. 2022). Subunits FeoA and FeoC are the same size and show very similar hydrophathy plots. Many Feo transport systems lack a FeoC subunit (e.g., see 9.A.8.1.19), and mutations in FeoA can eliminate the need for FeoC (see family description; Gómez-Garzón et al. 2022).	Bacteria	Pseudomonadota	FeoABC of Vibrio cholerae serotype O1 FeoA, 76 aas and possibly 1 central TMS, C3LP28 FeoB, 758 aas and 9 or 10 TMSs, C3LP27 FeoC, 76 aas and possibly 1 central TMS, C3LP26
9.A.8.1.19	FeoBA ferrous iron uptake system. There is no FeoC in this systems (Gómez-Garzón et al. 2022).	Bacteria	Pseudomonadota	FeoBA of Shewanella oneidensis (strain MR-1) FeoB, 764 aas and 9 or 10 TMSs, Q8EG28 FeoA, 76 aas and 0 TMSs, Q8EG29
9.A.8.1.20	FeoC-like transcriptional regulator of 95 aas. The N-terminal domain is the FeoC domain.	Bacteria	Actinomycetota	FeoC-like Tx regulator of Microbispora oryzae
9.A.8.1.21	FeoB of 776 aas and 9 TMSs in a 6 (residues 295 - 530) + 3 (residues 680 - 776) TMS arrangement. Down-regulation of iron/zinc ion transporters and toxin synthesis in Microcystis aeruginosa exposed to 5,4'-dihydroxyflavone has been documented (Yu et al. 2023).	Bacteria	Bacillati, Cyanobacteriota	FeoB of Microcystis aeruginosa