TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*5.A.1.1.1









Disulfide bond oxidoreductase-D, DsbD. of 565 aas and 9 TMSs.  DsbD provides reducing equivalents to a large array of periplasmic redox proteins. These proteins use the reducing power received from DsbD to correct non-native disulfides, mature c-type cytochromes, protect cysteines on secreted proteins from irreversible oxidation, reduce methionine sulfoxides, and scavenge reactive oxygen species such as hydrogen peroxide (Cho and Collet 2013). DsbD x-ray structures are known, revealing its unusual redox properties and extreme rigidity (Stirnimann et al. 2006).

Bacteria
Proteobacteria
DsbD of E.coli
*5.A.1.1.2









DsbD of 601 aas and 9 TMSs
Bacteria
Proteobacteria
DsbD of Neisseria meningitidis (Q9JTL9)
*5.A.1.2.1









Cytochrome c-type biogenesis protein, CcdA
Bacteria
Firmicutes
CcdA of Bacillus subtilis
*5.A.1.2.2









Cytochrome c biogenesis protein, CcdA

Bacteria
Actinobacteria
Cyt c biogenesis protein of Verrucosispora maris (F4FC13)
*5.A.1.2.3









Cytochrome c biogenesis protein, CcdA

Archaea
Euryarchaeota
CcdA of Methanosarcina mazei (Q8PY72)
*5.A.1.2.4









Cytochrome c biogenesis protein, CcdA

Eukaryota
Viridiplantae
CcdA of Chlamydomonas reinhardtii (Q8S3X4)
*5.A.1.2.5









Cytochrome c-type biogenesis CcdA-like chloroplastic protein (Cytochrome b6f biogenesis protein CCDA)

Eukaryota
Viridiplantae
CCDA of Arabidopsis thaliana
*5.A.1.2.6









Cytochrome c biogenesis protein of 242 aas and 7 putative TMSs.

Bacteria
Proteobacteria
Cytochrome c biogenesis protein of Burkholderia sp. BT03
*5.A.1.2.7









Transmembrane electron carrier, SoxV (CcdA-like protein), transferring electrons from the cytoplasm to SoxW, a perimplsmic thioredoxin; involved in thoisulfate oxidation (Appia-Ayme and Berks 2002).

Bacteria
Proteobacteria
SoxV of Rhodovulum sulfidophilum
*5.A.1.2.8









Cytochrome c-type biogenesis protein (CcdA) of 190 aas and 6 TMSs. The NMR structure of a reduced-state mimic of CcdA that transfers electrons across the inner membrane has been determined (Williamson et al. 2015).  The two cysteine positions in CcdA are separated by 20 Å. Whereas one is accessible to the cytoplasm, the other resides in the protein core, thus implying that conformational exchange is required for periplasmic accessibility, confirmed in vitro. The existence of multiple conformational states was demonstrated, suggesting a four-state model for relaying electrons from cytosolic to periplasmic redox substrates (Williamson et al. 2015).

Archaea
Euryarchaeota
CcdA of Archaeoglobus fulgidus
*5.A.1.2.9









CcdA family member, the thiol:disulfide excange protein, DipZ of 695 aas and 7 TMSs.  The 1.9Å resolution x-ray structure of the C-terminal ectodomain of Rv2874 revealed the predicted thioredoxin-like domain with its conserved Cys-X-X-Cys active-site motif, but this domain is combined with a second domain with a carbohydrate-binding module (CBM) fold (Goldstone et al. 2016). A cavity in the CBM adjacent to the thioredoxin active site suggested the presence of a carbohydrate-binding site.  Possibly, this allows an expansion of the thioredoxin-domain functionality to carbohydrate modification.

Bacteria
Actinobacteria
DipZ of Mycobacterium tuberculosis
*5.A.1.2.10









CcdA of 222 aas and 6 TMSs. The NMR structure in an oxidized and outward-facing state has been determined. CcdA consists of two inverted structural repeats of three transmembrane helices (2 x 3-TMSs). Zhou and Bushweller 2018 computationally modeled and experimentally validated an inward-facing state, which suggests that CcdA uses an elevator-type movement to shuttle the reactive cysteines across the membrane. Its structure may be relevant to other LysE superfamily transporters. Structure comparisons of CcdA, semiSWEET, Pnu, and major facilitator superfamily (MFS) transporters provide insights into membrane transporter architecture and mechanism (Zhou and Bushweller 2018).

Bacteria
Deinococcus-Thermus
CcdA of Thermus thermophilus
*5.A.1.3.1









Methylamine utilization protein, MauF
Bacteria
Proteobacteria
MauF of Paracoccus denitrificans
*5.A.1.4.1









Mercury resistance protein; mercuric ion reductase, MerA
Bacteria
Actinobacteria
MerA of Streptomyces lividans
*5.A.1.5.1









Suppressor of copper-sensitivity B, ScsB (Gupta et al. 1997). Part of a transmembrane peroxide reductase complex (Cho et al. 2012).

Bacteria
Proteobacteria
ScsB of Salmonella typhimurium
*5.A.1.5.2









Peroxide reductase complex component, ScsB (Cho et al. 2012).

Bacteria
Proteobacteria
ScsB opf Caulobacter crescentus
*5.A.1.5.3









ScsB homologue

Bacteria
Chlamydiae/Verrucomicrobia group
ScsB homologue of Parachlamydia acanthamoebae
*5.A.1.6.1









Heavy metal transport detoxicification protein (499aas; 7TMSs). Has an N-terminal heavy metal binding domain ( 70 aas) resembling MerP (1.A.72.3) and the metal binding N-terminal domains of family 5 & 6-type P-ATPases (3.A.3.5 and 3.A.3.6), a central DsbD domain and a C-terminal COG4633 domain (Gupta et al., 1997). COG4633 may also contain a metal ion binding domain homologous to but more distant in sequence from those in copper-ATPases.

Bacteria
Firmicutes
CycZ of Clostridium thermocellum (A3DGJ1)
*5.A.1.6.2









Dsb2 of 228 aas

Bacteria
Spirochaetes
Dsb2 of Leptospira meyeri
*5.A.1.6.3









Uncharacterized protein of 264 aas and 6 TMSs.

Archaea
Euryarchaeota
UP of Haloferax gibbonsii
*5.A.1.6.4









Ferric reductase of 410 aas and 11 putative TMSs with a C-terminal YedZ domain (TC#9.B.43).

Bacteria
Cyanobacteria
Ferric reductase of Anabaena cylindrica
*5.A.1.6.5









Uncharacterized protein of 221 aas and 6 TMSs

Bacteria
Proteobacteria
UP of Bdellovibrio exovorus