TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*5.B.2.1.1









Cytochrome b561 with an N-terminal cellobiose dehydrogenase (CDH)-like domain and a C-terminal cytb561 - FRRS1-like domain, both containing heme binding sites (Bérczi and Zimányi 2014).

Eukaryota
Metazoa
Cytb561 of Bos taurus (P10897)
*5.B.2.1.2









Tumor suppressor (Tsp10 pending protein)
Eukaryota
Metazoa
Tsp10 of Mus musculus (NP_062694)
*5.B.2.1.3









Duodenyl cytochrome b ferrireductase, Dcytb. Duodenyl L-Ascorbate (in):Fe3+ iron chelate (out) oxidoreduclase. Present in duodenal enterocyte brush boarder membranes (isoform 1); reduces dietary Fe3+ to Fe2+ to facilitate its transport into the mucosal cell. Binds two hemes non-covalently. Induced by iron deficiency. Also expressed in erythrocytes and respiratory epithelia (Lane and Lawen, 2009).  

Eukaryota
Metazoa
Duodenyl cytochrome b reductase of Homo sapiens (Q53TN4)
*5.B.2.1.4









Secretory vesicle-specific (chromafin granule) cytochrome b561 (isoform 2)

Eukaryota
Metazoa
Cytochrome b561 of Homo sapiens (P49447)
*5.B.2.1.5









The Lysosomal ascorbate:ferric chelate oxidoreductase, Cytochrome b561 (isoform 3).

Eukaryota
Metazoa
Lysosomal cytochrome b561 of Homo sapiens (Q6P1H1)
*5.B.2.1.6









Ascorbate-specific transmembrane electron transporter 1 (Cytochrome b561-1; Zmb561)

Eukaryota
Viridiplantae
ZCYB of Zea mays
*5.B.2.1.7









Cytochrome b561 ferric reductase (Glanfield et al. 2010).

Eukaryota
Metazoa
Cyt b561 of Schistosoma japonicum
*5.B.2.2.1









Ferric chelate reductase

Eukaryota
Viridiplantae
Ferric chelate reductase of Medicago truncatula
*5.B.2.2.2









Cytochrome b561 ferric reductase with N-terminal DOMON-related domain (for heme or sugar binding).

Eukaryota
Viridiplantae
Ferric reductase of Arabidopsis thaliana
*5.B.2.2.3









Ferric-chelate reductase 1. Involved in neurotransmitter synthesis and dietary iron uptake. (Picco et al. 2014).

Eukaryota
Metazoa
Ferric-chelate reductase 1 homologue of Drosophila melanogaster
*5.B.2.2.4









Ferric chelate reductase homologue (N-terminus; 5 TMSs; TC# 5.B.2; may reduce Cu2+ to Cu+) fused to a Ctr copper transporter (C-terminus; 3 TMSs; Ctr family, TC# 1.A.56).

Eukaryota
Bangiophyceae
Ctr fusion protein of Galdieria sulphuraria
*5.B.2.2.5









Uncharacterized protein of 535 aas and 5 C-terminal TMSs with an N-terminal DOMON domain and a C-terminal cytochrome b561 domain.

Eukaryota
Viridiplantae
UP of Chlamydomonas reinhardtii
*5.B.2.2.6









DOMON domain-containing protein FRRS1L precursor of 293 aas and 2 TMSs, one N-terminal and one central. Loss of Frrs1l disrupts synaptic AMPA receptor function, and results in neurodevelopmental, motor, cognitive and electrographical abnormalities (Stewart et al. 2019).

Eukaryota
Metazoa
FRRS1L of Mus musculus
*5.B.2.3.1









Uncharacterized protein of 403 aas and 6 TMSs in a 1 (N-termina) plus 5 TMS arrangement.

Eukaryota
Fungi
UP of Setosphaeria turcica (Northern leaf blight fungus) (Exserohilum turcicum)
*5.B.2.3.2









Uncharacterized protein with an N-terminal TMS followed by a heme binding cytochrome domain of fungal cellubiose dehydrogenases and a C-terminal Cytochrome b-561 / ferric reductase 5 TMS transmembrane domain of 453 aas.

Eukaryota
Fungi
UP of Hypocrea virens (Gliocladium virens) (Trichoderma virens)
*5.B.2.3.3









Uncharacterized putative cellobiose dehydrogenase of 476 aas and 6 (1 + 5) TMSs. These 5 TMSs may be homologous to those of the CBP family (9.B.306), but homology has not been established.

Eukaryota
Fungi
UP of Ophiocordyceps sinensis
*5.B.2.3.4









Uncharacterized protein of 563 aas and 6 TMSs in a 1 + 300 residues, largely hydrophilic + 5 TMSs. This protein is homologous to the proteins in the family with TC# 9.B.57.1.1 showing extensive sequence similarity.  The latter protein is the Mtp1 protein, essential for conidiation and conidial germination, of 520 aas and 12 TMSs (Lu et al. 2008). It has an N-terminal Cytb561 domain and a Ytp1 C-terminal domain.

Eukaryota
Fungi
UP of Neurospora crassa
*5.B.2.3.5









Uncharacterized protein of 272 aas and 6 TMSs

Eukaryota
Viridiplantae
UP of Glycine soja