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Protein

Cytochrome b5

Gene

CYB5A

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -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

Keywordsi

Biological processElectron transport, Transport
LigandHeme, Iron, Metal-binding

Enzyme and pathway databases

BioCyciMetaCyc: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

EuPathDBiHostDB:ENSG00000166347.18
HGNCiHGNC:2570 CYB5A
MIMi613218 gene
neXtProtiNX_P00167

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Topology

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

Keywords - Cellular componenti

Cytoplasm, Endoplasmic reticulum, Membrane, Microsome

Pathology & Biotechi

Involvement in diseasei

Methemoglobinemia and ambiguous genitalia (METAG)3 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionAn autosomal recessive disorder characterized by sex steroid deficiency but normal glucocorticoid and mineralocorticoid reserve, male undermasculinization, absent or disturbed pubertal development, decreased levels of erythrocyte cytochrome B5, and excessive amounts of methemoglobin in blood cells resulting in cyanosis and hypoxia.
See also OMIM:250790
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_08083327 – 134Missing in METAG. 1 PublicationAdd BLAST108
Natural variantiVAR_08083444H → L in METAG. 1 Publication1

Keywords - Diseasei

Disease mutation

Organism-specific databases

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

Chemistry databases

ChEMBLiCHEMBL6170
DrugBankiDB04009 Dimethyl Propionate Ester Heme

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
ProteomicsDBi12628 [P00167-2]
51226
51227 [P00167-2]
TopDownProteomicsiP00167-1 [P00167-1]
P00167-3 [P00167-3]

PTM databases

iPTMnetiP00167
PhosphoSitePlusiP00167

Expressioni

Gene expression databases

BgeeiENSG00000166347 Expressed in 233 organ(s), highest expression level in nephron tubule
CleanExiHS_CYB5A
ExpressionAtlasiP00167 baseline and differential
GenevisibleiP00167 HS

Organism-specific databases

HPAiCAB006333
HPA047548
HPA058547

Interactioni

GO - Molecular functioni

Protein-protein interaction databases

BioGridi107908, 25 interactors
IntActiP00167, 4 interactors
STRINGi9606.ENSP00000341625

Structurei

Secondary structure

1134
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details

3D structure databases

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

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
InterProiView protein in InterPro
IPR001199 Cyt_B5-like_heme/steroid-bd
IPR036400 Cyt_B5-like_heme/steroid_sf
IPR018506 Cyt_B5_heme-BS
PfamiView protein in Pfam
PF00173 Cyt-b5, 1 hit
PRINTSiPR00363 CYTOCHROMEB5
SMARTiView protein in SMART
SM01117 Cyt-b5, 1 hit
SUPFAMiSSF55856 SSF55856, 1 hit
PROSITEiView protein in PROSITE
PS00191 CYTOCHROME_B5_1, 1 hit
PS50255 CYTOCHROME_B5_2, 1 hit

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

This entry has 3 described isoforms and 1 potential isoform that is computationally mapped.Show allAlign All

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

Computationally mapped potential isoform sequencesi

There is 1 potential isoform mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
J3KNC7J3KNC7_HUMAN
Cytochrome b5
CYB5A
60Annotation score:

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

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_08083327 – 134Missing in METAG. 1 PublicationAdd BLAST108
Natural variantiVAR_08083444H → L in METAG. 1 Publication1

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

Similar proteinsi

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, 25 interactors
IntActiP00167, 4 interactors
STRINGi9606.ENSP00000341625

Chemistry databases

ChEMBLiCHEMBL6170
DrugBankiDB04009 Dimethyl Propionate Ester Heme

PTM databases

iPTMnetiP00167
PhosphoSitePlusiP00167

Polymorphism and mutation databases

BioMutaiCYB5A
DMDMi117809

Proteomic databases

EPDiP00167
MaxQBiP00167
PaxDbiP00167
PeptideAtlasiP00167
PRIDEiP00167
ProteomicsDBi12628 [P00167-2]
51226
51227 [P00167-2]
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
EuPathDBiHostDB:ENSG00000166347.18
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
621 Hereditary methemoglobinemia
PharmGKBiPA27068
GenAtlasiSearch...

Phylogenomic databases

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

Enzyme and pathway databases

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

Miscellaneous databases

ChiTaRSiCYB5A human
EvolutionaryTraceiP00167
GeneWikiiCytochrome_b5,_type_A
GenomeRNAii1528
PROiPR:P00167
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000166347 Expressed in 233 organ(s), highest expression level in nephron tubule
CleanExiHS_CYB5A
ExpressionAtlasiP00167 baseline and differential
GenevisibleiP00167 HS

Family and domain databases

Gene3Di3.10.120.10, 1 hit
InterProiView protein in InterPro
IPR001199 Cyt_B5-like_heme/steroid-bd
IPR036400 Cyt_B5-like_heme/steroid_sf
IPR018506 Cyt_B5_heme-BS
PfamiView protein in Pfam
PF00173 Cyt-b5, 1 hit
PRINTSiPR00363 CYTOCHROMEB5
SMARTiView protein in SMART
SM01117 Cyt-b5, 1 hit
SUPFAMiSSF55856 SSF55856, 1 hit
PROSITEiView protein in PROSITE
PS00191 CYTOCHROME_B5_1, 1 hit
PS50255 CYTOCHROME_B5_2, 1 hit
ProtoNetiSearch...

Entry informationi

Entry nameiCYB5_HUMAN
AccessioniPrimary (citable) accession number: P00167
Secondary accession number(s): A8MV91, F8WEU4, Q6IB14
Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: January 23, 2007
Last modified: November 7, 2018
This is version 199 of the entry and version 2 of the sequence. See 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. SIMILARITY comments
    Index of protein domains and families
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. Human chromosome 18
    Human chromosome 18: entries, gene names and cross-references to MIM
  6. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
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