ID   CYB5_ALOSE              Reviewed;          87 AA.
AC   P00168;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1989, sequence version 2.
DT   03-AUG-2022, entry version 104.
DE   RecName: Full=Cytochrome b5;
DE   Flags: Fragment;
GN   Name=CYB5A; Synonyms=CYB5;
OS   Alouatta seniculus (Red howler monkey).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Primates; Haplorrhini; Platyrrhini; Atelidae;
OC   Alouattinae; Alouatta.
OX   NCBI_TaxID=9503;
RN   [1]
RP   PROTEIN SEQUENCE.
RX   PubMed=4993957; DOI=10.1016/s0021-9258(18)62368-3;
RA   Nobrega F.G., Ozols J.;
RT   "Amino acid sequences of tryptic peptides of cytochromes b5 from microsomes
RT   of human, monkey, porcine, and chicken liver.";
RL   J. Biol. Chem. 246:1706-1717(1971).
RN   [2]
RP   SEQUENCE REVISION TO 11; 14; 85 AND 87.
RX   PubMed=2752049; DOI=10.1016/0167-4838(89)90143-x;
RA   Ozols J.;
RT   "Structure of cytochrome b5 and its topology in the microsomal membrane.";
RL   Biochim. Biophys. Acta 997:121-130(1989).
CC   -!- FUNCTION: Cytochrome b5 is a membrane-bound hemoprotein functioning as
CC       an electron 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   PIR; S07959; S07959.
DR   AlphaFoldDB; P00168; -.
DR   SMR; P00168; -.
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   Acetylation; Direct protein sequencing; Electron transport;
KW   Endoplasmic reticulum; Heme; Iron; Membrane; Metal-binding; Microsome;
KW   Transmembrane; Transport.
FT   CHAIN           1..>87
FT                   /note="Cytochrome b5"
FT                   /id="PRO_0000166007"
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   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   MOD_RES         6
FT                   /note="N6-acetyllysine"
FT                   /evidence="ECO:0000250|UniProtKB:P56395"
FT   MOD_RES         15
FT                   /note="N6-acetyllysine"
FT                   /evidence="ECO:0000250|UniProtKB:P56395"
FT   CONFLICT        11..14
FT                   /note="EEIQ -> QEIE (in Ref. 1; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        85..87
FT                   /note="RPK -> KPR (in Ref. 1; AA sequence)"
FT                   /evidence="ECO:0000305"
FT   NON_TER         87
SQ   SEQUENCE   87 AA;  10032 MW;  5B3552315D1A0F5C CRC64;
     SDEAVKYYTL EEIQKHNHSK STWLILHHKV YDLTKFLEEH PGGEEVLREQ AGGDATEDFE
     DVGHSTDARE LSKTYIIGEL HPDDRPK