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Protein

Cytochrome b5

Gene

Cyb5a

Organism
Rattus norvegicus (Rat)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Cytochrome b5 is a membrane bound hemoprotein which function as an electron carrier for several membrane bound oxygenases. It is also involved in several steps of the sterol biosynthesis pathway, particularly in the C-6 double bond introduction during the C-6 desaturation.

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Metal bindingi44 – 441Iron (heme axial ligand)
Metal bindingi68 – 681Iron (heme axial ligand)

GO - Molecular functioni

  • electron carrier activity Source: RGD
  • heme binding Source: InterPro
  • metal ion binding Source: UniProtKB-KW

GO - Biological processi

  • oxidation-reduction process Source: UniProtKB-KW
  • response to cadmium ion Source: RGD
Complete GO annotation...

Keywords - Biological processi

Electron transport, Transport

Keywords - Ligandi

Heme, Iron, Metal-binding

Enzyme and pathway databases

ReactomeiR-RNO-196836. Vitamin C (ascorbate) metabolism.

Names & Taxonomyi

Protein namesi
Recommended name:
Cytochrome b5
Gene namesi
Name:Cyb5a
Synonyms:Cyb5
OrganismiRattus norvegicus (Rat)
Taxonomic identifieri10116 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeRattus
Proteomesi
  • UP000002494 Componenti: Chromosome 18

Organism-specific databases

RGDi620558. Cyb5a.

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Transmembranei109 – 13123HelicalSequence analysisAdd
BLAST

GO - Cellular componenti

  • endoplasmic reticulum Source: HGNC
  • endoplasmic reticulum membrane Source: RGD
  • extracellular exosome Source: Ensembl
  • integral component of membrane Source: UniProtKB-KW
  • intracellular membrane-bounded organelle Source: RGD
  • mitochondrion Source: Ensembl
Complete GO annotation...

Keywords - Cellular componenti

Endoplasmic reticulum, Membrane, Microsome

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Initiator methionineiRemoved2 Publications
Chaini2 – 134133Cytochrome b5PRO_0000166014Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei2 – 21N-acetylalanine1 Publication
Modified residuei7 – 71N6-acetyllysineBy similarity
Modified residuei10 – 101N6-acetyllysineBy similarity
Modified residuei19 – 191N6-acetyllysineBy similarity

Keywords - PTMi

Acetylation

Proteomic databases

PaxDbiP00173.
PRIDEiP00173.

PTM databases

iPTMnetiP00173.

Expressioni

Gene expression databases

GenevisibleiP00173. RN.

Interactioni

Protein-protein interaction databases

IntActiP00173. 1 interaction.
MINTiMINT-4567938.
STRINGi10116.ENSRNOP00000020446.

Structurei

Secondary structure

1
134
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Helixi14 – 196Combined sources
Beta strandi21 – 244Combined sources
Beta strandi27 – 293Combined sources
Beta strandi34 – 363Combined sources
Helixi40 – 423Combined sources
Helixi47 – 526Combined sources
Turni53 – 564Combined sources
Helixi60 – 645Combined sources
Turni65 – 673Combined sources
Helixi70 – 745Combined sources
Helixi76 – 794Combined sources
Beta strandi80 – 845Combined sources
Helixi88 – 903Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1AQANMR-A6-99[»]
1AW3NMR-A6-99[»]
1AXXNMR-A6-99[»]
1B5ANMR-A6-99[»]
1B5BNMR-A6-99[»]
1BFXNMR-A1-99[»]
1BLVNMR-A6-99[»]
1I87NMR-A2-99[»]
1I8CNMR-A2-99[»]
1IB7NMR-A6-99[»]
1IETNMR-A2-99[»]
1IEUNMR-A2-99[»]
1JEXNMR-A6-99[»]
1MNYNMR-A6-99[»]
2AXXNMR-A6-99[»]
ProteinModelPortaliP00173.
SMRiP00173. Positions 6-99.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP00173.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini9 – 8577Cytochrome b5 heme-bindingPROSITE-ProRule annotationAdd
BLAST

Sequence similaritiesi

Belongs to the cytochrome b5 family.Curated
Contains 1 cytochrome b5 heme-binding domain.PROSITE-ProRule annotation

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG0537. Eukaryota.
COG5274. LUCA.
GeneTreeiENSGT00510000046507.
HOGENOMiHOG000039853.
HOVERGENiHBG002653.
InParanoidiP00173.
OMAiWTNWLIP.
OrthoDBiEOG78H3W2.
PhylomeDBiP00173.
TreeFamiTF314537.

Family and domain databases

Gene3Di3.10.120.10. 1 hit.
InterProiIPR001199. Cyt_B5-like_heme/steroid-bd.
IPR018506. Cyt_B5_heme-BS.
[Graphical view]
PfamiPF00173. Cyt-b5. 1 hit.
[Graphical view]
PRINTSiPR00363. CYTOCHROMEB5.
SMARTiSM01117. Cyt-b5. 1 hit.
[Graphical view]
SUPFAMiSSF55856. SSF55856. 1 hit.
PROSITEiPS00191. CYTOCHROME_B5_1. 1 hit.
PS50255. CYTOCHROME_B5_2. 1 hit.
[Graphical view]

Sequences (2)i

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

This entry describes 2 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform Long (identifier: P00173-1) [UniParc]FASTAAdd to basket

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

« Hide

        10         20         30         40         50
MAEQSDKDVK YYTLEEIQKH KDSKSTWVIL HHKVYDLTKF LEEHPGGEEV
60 70 80 90 100
LREQAGGDAT ENFEDVGHST DARELSKTYI IGELHPDDRS KIAKPSETLI
110 120 130
TTVESNSSWW TNWVIPAISA LVVALMYRLY MAED
Length:134
Mass (Da):15,355
Last modified:January 23, 2007 - v2
Checksum:i37568069CA88CCD2
GO
Isoform Short (identifier: P00173-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     97-100: ETLI → HSAL
     101-134: Missing.

Show »
Length:100
Mass (Da):11,407
Checksum:i8D8AC05DCA93F37D
GO

Experimental Info

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sequence conflicti18 – 181Q → E AA sequence (PubMed:6840088).Curated

Alternative sequence

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Alternative sequencei97 – 1004ETLI → HSAL in isoform Short. CuratedVSP_001246
Alternative sequencei101 – 13434Missing in isoform Short. CuratedVSP_001247Add
BLAST

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
D13205 mRNA. Translation: BAA02492.1.
AF007107 mRNA. Translation: AAB67609.1.
AF007108 mRNA. Translation: AAB67610.1.
BC086945 mRNA. Translation: AAH86945.1.
PIRiJC5596.
S28404. CBRT5.
RefSeqiNP_071581.1. NM_022245.1. [P00173-1]
UniGeneiRn.1055.

Genome annotation databases

EnsembliENSRNOT00000020446; ENSRNOP00000020446; ENSRNOG00000015205. [P00173-1]
GeneIDi64001.
KEGGirno:64001.

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
D13205 mRNA. Translation: BAA02492.1.
AF007107 mRNA. Translation: AAB67609.1.
AF007108 mRNA. Translation: AAB67610.1.
BC086945 mRNA. Translation: AAH86945.1.
PIRiJC5596.
S28404. CBRT5.
RefSeqiNP_071581.1. NM_022245.1. [P00173-1]
UniGeneiRn.1055.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
1AQANMR-A6-99[»]
1AW3NMR-A6-99[»]
1AXXNMR-A6-99[»]
1B5ANMR-A6-99[»]
1B5BNMR-A6-99[»]
1BFXNMR-A1-99[»]
1BLVNMR-A6-99[»]
1I87NMR-A2-99[»]
1I8CNMR-A2-99[»]
1IB7NMR-A6-99[»]
1IETNMR-A2-99[»]
1IEUNMR-A2-99[»]
1JEXNMR-A6-99[»]
1MNYNMR-A6-99[»]
2AXXNMR-A6-99[»]
ProteinModelPortaliP00173.
SMRiP00173. Positions 6-99.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

IntActiP00173. 1 interaction.
MINTiMINT-4567938.
STRINGi10116.ENSRNOP00000020446.

PTM databases

iPTMnetiP00173.

Proteomic databases

PaxDbiP00173.
PRIDEiP00173.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENSRNOT00000020446; ENSRNOP00000020446; ENSRNOG00000015205. [P00173-1]
GeneIDi64001.
KEGGirno:64001.

Organism-specific databases

CTDi1528.
RGDi620558. Cyb5a.

Phylogenomic databases

eggNOGiKOG0537. Eukaryota.
COG5274. LUCA.
GeneTreeiENSGT00510000046507.
HOGENOMiHOG000039853.
HOVERGENiHBG002653.
InParanoidiP00173.
OMAiWTNWLIP.
OrthoDBiEOG78H3W2.
PhylomeDBiP00173.
TreeFamiTF314537.

Enzyme and pathway databases

ReactomeiR-RNO-196836. Vitamin C (ascorbate) metabolism.

Miscellaneous databases

EvolutionaryTraceiP00173.
PROiP00173.

Gene expression databases

GenevisibleiP00173. RN.

Family and domain databases

Gene3Di3.10.120.10. 1 hit.
InterProiIPR001199. Cyt_B5-like_heme/steroid-bd.
IPR018506. Cyt_B5_heme-BS.
[Graphical view]
PfamiPF00173. Cyt-b5. 1 hit.
[Graphical view]
PRINTSiPR00363. CYTOCHROMEB5.
SMARTiSM01117. Cyt-b5. 1 hit.
[Graphical view]
SUPFAMiSSF55856. SSF55856. 1 hit.
PROSITEiPS00191. CYTOCHROME_B5_1. 1 hit.
PS50255. CYTOCHROME_B5_2. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  1. "The carboxy-terminal 10 amino acid residues of cytochrome b5 are necessary for its targeting to the endoplasmic reticulum."
    Mitoma J.-Y., Ito A.
    EMBO J. 11:4197-4203(1992) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].
  2. "Identification of two homologous cytochrome b5s in rat brain."
    Yoo M.
    Biochem. Biophys. Res. Commun. 236:641-642(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA], ALTERNATIVE SPLICING.
    Strain: Sprague-Dawley.
    Tissue: Brain.
  3. "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
    The MGC Project Team
    Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM LONG).
    Tissue: Liver.
  4. "Chemical structure of rat liver cytochrome b5. Isolation of peptides by high-pressure liquid chromatography."
    Ozols J., Heinemann F.S.
    Biochim. Biophys. Acta 704:163-173(1982) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 2-134, CLEAVAGE OF INITIATOR METHIONINE, ACETYLATION AT ALA-2.
  5. "Structure of cytochrome b5 and its topology in the microsomal membrane."
    Ozols J.
    Biochim. Biophys. Acta 997:121-130(1989) [PubMed] [Europe PMC] [Abstract]
    Cited for: PROTEIN SEQUENCE OF 2-11.
  6. Cited for: PROTEIN SEQUENCE OF 7-89.
  7. "Design challenges for hemoproteins: the solution structure of apocytochrome b5."
    Falzone C.J., Mayer M.R., Whiteman E.L., Moore C.D., Lecomte J.T.J.
    Biochemistry 35:6519-6526(1996) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR OF 1-99.
  8. "Solution structure of reduced microsomal rat cytochrome b5."
    Banci L., Bertini I., Ferroni F., Rosato A.
    Eur. J. Biochem. 249:270-279(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR OF 6-99.
  9. "The solution structure of oxidized rat microsomal cytochrome b5."
    Arnesano F., Banci L., Bertini I., Felli I.C.
    Biochemistry 37:173-184(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR OF 6-99.
  10. "The origin of differences in the physical properties of the equilibrium forms of cytochrome b5 revealed through high-resolution NMR structures and backbone dynamic analyses."
    Dangi B., Sarma S., Yan C., Banville D.L., Guiles R.D.
    Biochemistry 37:8289-8302(1998) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR OF 6-99.
  11. "Structural and dynamic perturbations induced by heme binding in cytochrome b5."
    Falzone C.J., Wang Y., Vu B.C., Scott N.L., Bhattacharya S., Lecomte J.T.J.
    Biochemistry 40:4879-4891(2001) [PubMed] [Europe PMC] [Abstract]
    Cited for: STRUCTURE BY NMR OF 1-99.

Entry informationi

Entry nameiCYB5_RAT
AccessioniPrimary (citable) accession number: P00173
Secondary accession number(s): O35768
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: January 23, 2007
Last modified: June 8, 2016
This is version 154 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.