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Protein

Cytochrome b5

Gene

CYB5A

Organism
Homo sapiens (Human)
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.

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Metal bindingi44Iron (heme axial ligand)1
Metal bindingi68Iron (heme axial ligand)1

GO - Molecular functioni

  • aldo-keto reductase (NADP) activity Source: Reactome
  • cytochrome-c oxidase activity Source: ProtInc
  • enzyme binding Source: BHF-UCL
  • heme binding Source: InterPro
  • metal ion binding Source: UniProtKB-KW

GO - Biological processi

Complete GO annotation...

Keywords - Biological processi

Electron transport, Transport

Keywords - Ligandi

Heme, Iron, Metal-binding

Enzyme and pathway databases

BioCyciMetaCyc:ENSG00000166347-MONOMER.
ZFISH:ENSG00000166347-MONOMER.
ReactomeiR-HSA-196836. Vitamin C (ascorbate) metabolism.

Names & Taxonomyi

Protein namesi
Recommended name:
Cytochrome b5
Alternative name(s):
Microsomal cytochrome b5 type A
Short name:
MCB5
Gene namesi
Name:CYB5A
Synonyms:CYB5
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 18

Organism-specific databases

HGNCiHGNC:2570. CYB5A.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Transmembranei109 – 131HelicalSequence analysisAdd BLAST23

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Cytoplasm, Endoplasmic reticulum, Membrane, Microsome

Pathology & Biotechi

Involvement in diseasei

Methemoglobinemia CYB5A-related (METHB-CYB5A)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA form of methemoglobinemia, a hematologic disease characterized by the presence of excessive amounts of methemoglobin in blood cells, resulting in decreased oxygen carrying capacity of the blood, cyanosis and hypoxia.
See also OMIM:250790

Organism-specific databases

DisGeNETi1528.
MalaCardsiCYB5A.
MIMi250790. phenotype.
OpenTargetsiENSG00000166347.
Orphaneti90796. 46,XY disorder of sex development due to isolated 17,20 lyase deficiency.
PharmGKBiPA27068.

Chemistry databases

ChEMBLiCHEMBL6170.

Polymorphism and mutation databases

BioMutaiCYB5A.
DMDMi117809.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Initiator methionineiRemoved5 Publications
ChainiPRO_00001660102 – 134Cytochrome b5Add BLAST133

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei2N-acetylalanine1 Publication1
Modified residuei10N6-acetyllysineBy similarity1
Modified residuei19N6-acetyllysineBy similarity1

Keywords - PTMi

Acetylation

Proteomic databases

EPDiP00167.
MaxQBiP00167.
PaxDbiP00167.
PeptideAtlasiP00167.
PRIDEiP00167.
TopDownProteomicsiP00167-1. [P00167-1]
P00167-3. [P00167-3]

PTM databases

iPTMnetiP00167.
PhosphoSitePlusiP00167.

Expressioni

Gene expression databases

BgeeiENSG00000166347.
CleanExiHS_CYB5A.
ExpressionAtlasiP00167. baseline and differential.
GenevisibleiP00167. HS.

Organism-specific databases

HPAiCAB006333.
HPA047548.
HPA058547.

Interactioni

GO - Molecular functioni

  • enzyme binding Source: BHF-UCL

Protein-protein interaction databases

BioGridi107908. 23 interactors.
IntActiP00167. 4 interactors.
MINTiMINT-3003425.
STRINGi9606.ENSP00000341625.

Structurei

Secondary structure

1134
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi3 – 5Combined sources3
Helixi14 – 17Combined sources4
Helixi18 – 20Combined sources3
Beta strandi25 – 36Combined sources12
Turni38 – 43Combined sources6
Helixi49 – 52Combined sources4
Beta strandi55 – 58Combined sources4
Helixi61 – 65Combined sources5
Helixi70 – 75Combined sources6
Helixi76 – 78Combined sources3
Beta strandi80 – 84Combined sources5
Turni86 – 88Combined sources3
Turni91 – 93Combined sources3
Beta strandi96 – 100Combined sources5

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
2I96NMR-A1-108[»]
ProteinModelPortaliP00167.
SMRiP00167.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP00167.

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini9 – 85Cytochrome b5 heme-bindingPROSITE-ProRule annotationAdd BLAST77

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.
InParanoidiP00167.
OMAiFKSTWII.
OrthoDBiEOG091G17G8.
PhylomeDBiP00167.
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 (3)i

Sequence statusi: Complete.

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

This entry describes 3 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: P00167-1) [UniParc]FASTAAdd to basket
Also known as: Liver, Membrane-bound

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
MAEQSDEAVK YYTLEEIQKH NHSKSTWLIL HHKVYDLTKF LEEHPGGEEV
60 70 80 90 100
LREQAGGDAT ENFEDVGHST DAREMSKTFI IGELHPDDRP KLNKPPETLI
110 120 130
TTIDSSSSWW TNWVIPAISA VAVALMYRLY MAED
Length:134
Mass (Da):15,330
Last modified:January 23, 2007 - v2
Checksum:iB6AD2AB747555048
GO
Isoform 2 (identifier: P00167-2) [UniParc]FASTAAdd to basket
Also known as: Erythrocyte, Cytoplasmic

The sequence of this isoform differs from the canonical sequence as follows:
     98-98: T → P
     99-134: Missing.

Note: May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay.
Show »
Length:98
Mass (Da):11,268
Checksum:i62D9B54C7BCDF9F3
GO
Isoform 3 (identifier: P00167-3) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     86-95: Missing.

Note: No experimental confirmation available.
Show »
Length:124
Mass (Da):14,169
Checksum:iAC952456B4827706
GO

Sequence cautioni

The sequence AAA63169 differs from that shown. Reason: Erroneous gene model prediction.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti2 – 4Missing AA sequence (PubMed:4993957).Curated3
Sequence conflicti4Q → E AA sequence (PubMed:2752049).Curated1
Sequence conflicti15 – 18EEIQ → QEIE AA sequence (PubMed:4993957).Curated4
Sequence conflicti15 – 18EEIQ → QEIE AA sequence (PubMed:5062820).Curated4
Sequence conflicti15 – 18EEIQ → QEIE AA sequence (PubMed:4770377).Curated4
Sequence conflicti22Missing AA sequence (PubMed:4770377).Curated1
Sequence conflicti52R → W in CA771478 (Ref. 4) Curated1
Sequence conflicti62N → D AA sequence (PubMed:4993957).Curated1
Sequence conflicti62N → D AA sequence (PubMed:5062820).Curated1
Sequence conflicti62N → D AA sequence (PubMed:4770377).Curated1
Sequence conflicti89 – 91RPK → KPR AA sequence (PubMed:4030743).Curated3
Sequence conflicti89 – 91RPK → KPR AA sequence (PubMed:4993957).Curated3
Sequence conflicti89 – 91RPK → KPR AA sequence (PubMed:5062820).Curated3
Sequence conflicti89 – 91RPK → KPR AA sequence (PubMed:4770377).Curated3
Sequence conflicti122A → V AA sequence (PubMed:2752049).Curated1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_04536786 – 95Missing in isoform 3. 1 Publication10
Alternative sequenceiVSP_00124098T → P in isoform 2. 1 Publication1
Alternative sequenceiVSP_00124199 – 134Missing in isoform 2. 1 PublicationAdd BLAST36

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M22865 mRNA. Translation: AAA35729.1.
M60174 mRNA. Translation: AAA52165.1.
L39945
, L39792, L39941, L39942, L39943, L39944 Genomic DNA. Translation: AAA63169.1. Sequence problems.
CA771478 mRNA. No translation available.
CR456990 mRNA. Translation: CAG33271.1.
AC090398 Genomic DNA. No translation available.
CH471117 Genomic DNA. Translation: EAW66544.1.
BC015182 mRNA. Translation: AAH15182.1.
CCDSiCCDS12004.1. [P00167-1]
CCDS12005.1. [P00167-2]
CCDS54188.1. [P00167-3]
PIRiA28936. CBHU5.
JN0075. CBHU5E.
RefSeqiNP_001177736.1. NM_001190807.2. [P00167-3]
NP_001905.1. NM_001914.3. [P00167-2]
NP_683725.1. NM_148923.3. [P00167-1]
XP_011524137.1. XM_011525835.2. [P00167-2]
UniGeneiHs.465413.

Genome annotation databases

EnsembliENST00000340533; ENSP00000341625; ENSG00000166347. [P00167-1]
ENST00000397914; ENSP00000381011; ENSG00000166347. [P00167-3]
ENST00000494131; ENSP00000436461; ENSG00000166347. [P00167-2]
GeneIDi1528.
KEGGihsa:1528.
UCSCiuc002llh.4. human. [P00167-1]

Keywords - Coding sequence diversityi

Alternative splicing

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M22865 mRNA. Translation: AAA35729.1.
M60174 mRNA. Translation: AAA52165.1.
L39945
, L39792, L39941, L39942, L39943, L39944 Genomic DNA. Translation: AAA63169.1. Sequence problems.
CA771478 mRNA. No translation available.
CR456990 mRNA. Translation: CAG33271.1.
AC090398 Genomic DNA. No translation available.
CH471117 Genomic DNA. Translation: EAW66544.1.
BC015182 mRNA. Translation: AAH15182.1.
CCDSiCCDS12004.1. [P00167-1]
CCDS12005.1. [P00167-2]
CCDS54188.1. [P00167-3]
PIRiA28936. CBHU5.
JN0075. CBHU5E.
RefSeqiNP_001177736.1. NM_001190807.2. [P00167-3]
NP_001905.1. NM_001914.3. [P00167-2]
NP_683725.1. NM_148923.3. [P00167-1]
XP_011524137.1. XM_011525835.2. [P00167-2]
UniGeneiHs.465413.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
2I96NMR-A1-108[»]
ProteinModelPortaliP00167.
SMRiP00167.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi107908. 23 interactors.
IntActiP00167. 4 interactors.
MINTiMINT-3003425.
STRINGi9606.ENSP00000341625.

Chemistry databases

ChEMBLiCHEMBL6170.

PTM databases

iPTMnetiP00167.
PhosphoSitePlusiP00167.

Polymorphism and mutation databases

BioMutaiCYB5A.
DMDMi117809.

Proteomic databases

EPDiP00167.
MaxQBiP00167.
PaxDbiP00167.
PeptideAtlasiP00167.
PRIDEiP00167.
TopDownProteomicsiP00167-1. [P00167-1]
P00167-3. [P00167-3]

Protocols and materials databases

DNASUi1528.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000340533; ENSP00000341625; ENSG00000166347. [P00167-1]
ENST00000397914; ENSP00000381011; ENSG00000166347. [P00167-3]
ENST00000494131; ENSP00000436461; ENSG00000166347. [P00167-2]
GeneIDi1528.
KEGGihsa:1528.
UCSCiuc002llh.4. human. [P00167-1]

Organism-specific databases

CTDi1528.
DisGeNETi1528.
GeneCardsiCYB5A.
HGNCiHGNC:2570. CYB5A.
HPAiCAB006333.
HPA047548.
HPA058547.
MalaCardsiCYB5A.
MIMi250790. phenotype.
613218. gene.
neXtProtiNX_P00167.
OpenTargetsiENSG00000166347.
Orphaneti90796. 46,XY disorder of sex development due to isolated 17,20 lyase deficiency.
PharmGKBiPA27068.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiKOG0537. Eukaryota.
COG5274. LUCA.
GeneTreeiENSGT00510000046507.
HOGENOMiHOG000039853.
HOVERGENiHBG002653.
InParanoidiP00167.
OMAiFKSTWII.
OrthoDBiEOG091G17G8.
PhylomeDBiP00167.
TreeFamiTF314537.

Enzyme and pathway databases

BioCyciMetaCyc:ENSG00000166347-MONOMER.
ZFISH:ENSG00000166347-MONOMER.
ReactomeiR-HSA-196836. Vitamin C (ascorbate) metabolism.

Miscellaneous databases

ChiTaRSiCYB5A. human.
EvolutionaryTraceiP00167.
GeneWikiiCytochrome_b5,_type_A.
GenomeRNAii1528.
PROiP00167.
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000166347.
CleanExiHS_CYB5A.
ExpressionAtlasiP00167. baseline and differential.
GenevisibleiP00167. HS.

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...

Entry informationi

Entry nameiCYB5_HUMAN
AccessioniPrimary (citable) accession number: P00167
Secondary accession number(s): A8MV91, F8WEU4, Q6IB14
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: January 23, 2007
Last modified: November 2, 2016
This is version 186 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

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

Documents

  1. Human chromosome 18
    Human chromosome 18: entries, gene names and cross-references to MIM
  2. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  3. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  4. 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.