TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(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 may interact 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).

Bacteria
Proteobacteria
FeoAB of E. coli
FeoA (P0AEL3)
FeoB (P33650)
*9.A.8.1.2









Ferrous iron uptake system
Bacteria
Proteobacteria
FeoB of Helicobacter pylori
*9.A.8.1.3









Ferrous iron uptake system
Bacteria
Cyanobacteria
FeoB (slr1392) of Synechocystis PCC6803
*9.A.8.1.4









Ferrous iron uptake system, FeoB (Louvel et al., 2005)
Bacteria
Spirochaetes
FeoB of Leptospira biflexa (AAU93398)
*9.A.8.1.5









Ferrous iron (Fe2+) uptake system, FeoB1 (Dashper et al., 2005)
Bacteria
Bacteroidetes/Chlorobi group
FeoB1 of Porphyromonas gingivalis (AAQ66162)
*9.A.8.1.6









Manganous ion (Mn2+) uptake system, FeoB2 (Dashper et al., 2005)

Bacteria
Bacteroidetes/Chlorobi group
FeoB2 of Porphyromonas gingivalis (AAQ66370)
*9.A.8.1.7









FeoAB of 704 and 84 aas, respectively (Uebe and Schüler 2016).

Bacteria
Proteobacteria
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 75aa 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).

Bacteria
Proteobacteria
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
Proteobacteria
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
Proteobacteria
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
Bacteroidetes
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
Firmicutes
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
Proteobacteria
FeoB of Pseudomonas aeruginosa
*9.A.8.1.16









FeoA2B2 of 78 and 788 aas, respectively.

Bacteria
Proteobacteria
FeoA2B2 of Magnetospirillum gryphiswaldense MSR-1 v2