ID   CYB5_RHIST              Reviewed;         131 AA.
AC   Q9HFV1;
DT   05-MAR-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2001, sequence version 1.
DT   03-AUG-2022, entry version 71.
DE   RecName: Full=Cytochrome b5;
OS   Rhizopus stolonifer (Rhizopus nigricans).
OC   Eukaryota; Fungi; Fungi incertae sedis; Mucoromycota; Mucoromycotina;
OC   Mucoromycetes; Mucorales; Mucorineae; Rhizopodaceae; Rhizopus.
OX   NCBI_TaxID=4846;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=11523811; DOI=10.1007/s004380100492;
RA   Kunic B., Truan G., Breskvar K., Pompon D.;
RT   "Functional cloning, based on azole resistance in Saccharomyces cerevisiae,
RT   and characterization of Rhizopus nigricans redox carriers that are
RT   differentially involved in the P450-dependent response to progesterone
RT   stress.";
RL   Mol. Genet. Genomics 265:930-940(2001).
CC   -!- FUNCTION: Membrane bound hemoprotein which function as an electron
CC       carrier for several membrane bound oxygenases. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000250};
CC       Single-pass membrane protein {ECO:0000250}; Cytoplasmic side
CC       {ECO:0000250}. Microsome membrane {ECO:0000250}; Single-pass membrane
CC       protein {ECO:0000250}; Cytoplasmic side {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the cytochrome b5 family. {ECO:0000305}.
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DR   EMBL; AF290427; AAG23835.1; -; mRNA.
DR   AlphaFoldDB; Q9HFV1; -.
DR   SMR; Q9HFV1; -.
DR   GO; GO:0005789; C:endoplasmic reticulum membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0020037; F:heme binding; IEA:InterPro.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   Gene3D; 3.10.120.10; -; 1.
DR   InterPro; IPR001199; Cyt_B5-like_heme/steroid-bd.
DR   InterPro; IPR036400; Cyt_B5-like_heme/steroid_sf.
DR   InterPro; IPR018506; Cyt_B5_heme-BS.
DR   Pfam; PF00173; Cyt-b5; 1.
DR   PRINTS; PR00363; CYTOCHROMEB5.
DR   SMART; SM01117; Cyt-b5; 1.
DR   SUPFAM; SSF55856; SSF55856; 1.
DR   PROSITE; PS00191; CYTOCHROME_B5_1; 1.
DR   PROSITE; PS50255; CYTOCHROME_B5_2; 1.
PE   2: Evidence at transcript level;
KW   Electron transport; Endoplasmic reticulum; Heme; Iron; Membrane;
KW   Metal-binding; Microsome; Transmembrane; Transmembrane helix; Transport.
FT   CHAIN           1..131
FT                   /note="Cytochrome b5"
FT                   /id="PRO_0000166032"
FT   TRANSMEM        108..125
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          3..79
FT                   /note="Cytochrome b5 heme-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
FT   BINDING         38
FT                   /ligand="heme"
FT                   /ligand_id="ChEBI:CHEBI:30413"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
FT   BINDING         62
FT                   /ligand="heme"
FT                   /ligand_id="ChEBI:CHEBI:30413"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
SQ   SEQUENCE   131 AA;  14651 MW;  589D7413C768F2F0 CRC64;
     MTAKIFSLDE VSKHKTKSDL WVVIHNKVYD ITRFVVEHPG GEEVLVDEGG KDATEAFEDI
     GHSDEAREML EEYLIGSLDE ASRTKEYNVN VIRAGELPEE KKGSSLRIIL PALAIIGALV
     YKYVIVPKAH Q