ID   CYB5_BRAOB              Reviewed;         134 AA.
AC   P40934;
DT   01-FEB-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1995, sequence version 1.
DT   03-AUG-2022, entry version 98.
DE   RecName: Full=Cytochrome b5;
GN   Name=CYB5;
OS   Brassica oleracea var. botrytis (Cauliflower).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; malvids; Brassicales; Brassicaceae; Brassiceae; Brassica.
OX   NCBI_TaxID=3715;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND PROTEIN SEQUENCE OF 6-47 AND 75-89.
RC   STRAIN=subvar. cauliflora;
RX   PubMed=16668997; DOI=10.1104/pp.99.3.1254;
RA   Kearns E.V., Keck P., Somerville C.R.;
RT   "Primary structure of cytochrome b5 from cauliflower (Brassica oleracea L.)
RT   deduced from peptide and cDNA sequences.";
RL   Plant Physiol. 99:1254-1257(1992).
CC   -!- FUNCTION: Membrane bound hemoprotein which function as an electron
CC       carrier for several membrane bound oxygenases.
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; M87514; AAA32990.1; -; mRNA.
DR   PIR; T14454; T14454.
DR   AlphaFoldDB; P40934; -.
DR   SMR; P40934; -.
DR   PRIDE; P40934; -.
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   1: Evidence at protein level;
KW   Direct protein sequencing; Electron transport; Endoplasmic reticulum; Heme;
KW   Iron; Membrane; Metal-binding; Microsome; Transmembrane;
KW   Transmembrane helix; Transport.
FT   CHAIN           1..134
FT                   /note="Cytochrome b5"
FT                   /id="PRO_0000166023"
FT   TRANSMEM        107..127
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   DOMAIN          5..81
FT                   /note="Cytochrome b5 heme-binding"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00279"
FT   BINDING         40
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         64
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   VARIANT         5
FT                   /note="K -> N"
SQ   SEQUENCE   134 AA;  15062 MW;  764DC24A4CDDD591 CRC64;
     MASEKKVLGF EEVSQHNKTK DCWLIISGKV YDVTPFMDDH PGGDEVLLSS TGKDATNDFE
     DVGHSDTARD MMEKYYIGEI DSSTVPATRT YVAPVQPAYN QDKTPEFMIK ILQFLVPILI
     LGLALVVRQY TKKE