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Protein

Cytochrome b

Gene

COB

Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex) that is part of the mitochondrial respiratory chain. The b-c1 complex mediates electron transfer from ubiquinol to cytochrome c. Contributes to the generation of a proton gradient across the mitochondrial membrane that is then used for ATP synthesis.2 Publications

Cofactori

heme2 PublicationsNote: Binds 2 heme groups non-covalently.2 Publications

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Metal bindingi82Iron 1 (heme b562 axial ligand)Combined sources2 Publications1
Metal bindingi96Iron 2 (heme b566 axial ligand)Combined sources2 Publications1
Metal bindingi183Iron 1 (heme b562 axial ligand)Combined sources2 Publications1
Metal bindingi197Iron 2 (heme b566 axial ligand)Combined sources2 Publications1
Binding sitei202UbiquinoneBy similarity1

GO - Molecular functioni

GO - Biological processi

  • aerobic respiration Source: SGD
  • mitochondrial electron transport, ubiquinol to cytochrome c Source: UniProtKB
Complete GO annotation...

Keywords - Biological processi

Electron transport, Respiratory chain, Transport

Keywords - Ligandi

Heme, Iron, Metal-binding, Ubiquinone

Enzyme and pathway databases

BioCyciYEAST:Q0105-MONOMER.

Protein family/group databases

TCDBi3.D.3.3.1. the proton-translocating quinol:cytochrome c reductase (qcr) superfamily.

Names & Taxonomyi

Protein namesi
Recommended name:
Cytochrome b
Alternative name(s):
Complex III subunit 3
Complex III subunit CYTB
Complex III subunit III
Cytochrome b-c1 complex subunit 3
Cytochrome b-c1 complex subunit CYTB
Ubiquinol-cytochrome-c reductase complex cytochrome b subunit
Gene namesi
Name:COB
Synonyms:CYTB
Ordered Locus Names:Q0105
Encoded oniMitochondrion
OrganismiSaccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Taxonomic identifieri559292 [NCBI]
Taxonomic lineageiEukaryotaFungiDikaryaAscomycotaSaccharomycotinaSaccharomycetesSaccharomycetalesSaccharomycetaceaeSaccharomyces
Proteomesi
  • UP000002311 Componenti: Mitochondrion

Organism-specific databases

EuPathDBiFungiDB:Q0105.
SGDiS000007270. COB.

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Transmembranei32 – 52HelicalCombined sources2 PublicationsAdd BLAST21
Transmembranei76 – 98HelicalCombined sources2 PublicationsAdd BLAST23
Transmembranei113 – 133HelicalCombined sources2 PublicationsAdd BLAST21
Transmembranei179 – 199HelicalCombined sources2 PublicationsAdd BLAST21
Transmembranei225 – 245HelicalCombined sources2 PublicationsAdd BLAST21
Transmembranei289 – 309HelicalCombined sources2 PublicationsAdd BLAST21
Transmembranei321 – 341HelicalCombined sources2 PublicationsAdd BLAST21
Transmembranei348 – 368HelicalCombined sources2 PublicationsAdd BLAST21

GO - Cellular componenti

  • integral component of mitochondrial inner membrane Source: UniProtKB
  • mitochondrial respiratory chain complex III Source: UniProtKB
Complete GO annotation...

Keywords - Cellular componenti

Membrane, Mitochondrion, Mitochondrion inner membrane

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000617691 – 385Cytochrome bAdd BLAST385

Proteomic databases

PRIDEiP00163.
TopDownProteomicsiP00163.

Interactioni

Subunit structurei

Fungal cytochrome b-c1 complex contains 10 subunits; 3 respiratory subunits, 2 core proteins and 5 low-molecular weight proteins. Cytochrome b-c1 complex is a homodimer.3 Publications

Protein-protein interaction databases

BioGridi34779. 30 interactors.
IntActiP00163. 2 interactors.
MINTiMINT-4981526.

Structurei

Secondary structure

1385
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi3 – 6Combined sources4
Helixi10 – 17Combined sources8
Beta strandi21 – 23Combined sources3
Helixi28 – 31Combined sources4
Helixi32 – 51Combined sources20
Turni58 – 60Combined sources3
Helixi61 – 70Combined sources10
Helixi75 – 102Combined sources28
Turni103 – 106Combined sources4
Turni108 – 110Combined sources3
Helixi111 – 135Combined sources25
Helixi138 – 149Combined sources12
Helixi150 – 153Combined sources4
Turni155 – 157Combined sources3
Helixi158 – 166Combined sources9
Beta strandi168 – 171Combined sources4
Helixi173 – 204Combined sources32
Beta strandi217 – 220Combined sources4
Turni221 – 223Combined sources3
Helixi224 – 246Combined sources23
Turni248 – 251Combined sources4
Helixi254 – 257Combined sources4
Helixi273 – 275Combined sources3
Helixi276 – 283Combined sources8
Beta strandi285 – 287Combined sources3
Helixi288 – 300Combined sources13
Helixi301 – 304Combined sources4
Helixi305 – 308Combined sources4
Beta strandi312 – 316Combined sources5
Helixi320 – 340Combined sources21
Helixi348 – 364Combined sources17
Helixi366 – 380Combined sources15

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1EZVX-ray2.30C1-385[»]
1KB9X-ray2.30C1-385[»]
1KYOX-ray2.97C/N1-385[»]
1P84X-ray2.50C1-385[»]
2IBZX-ray2.30C1-385[»]
3CX5X-ray1.90C/N1-385[»]
3CXHX-ray2.50C/N1-385[»]
4PD4X-ray3.04C1-385[»]
ProteinModelPortaliP00163.
SMRiP00163.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP00163.

Family & Domainsi

Sequence similaritiesi

Belongs to the cytochrome b family.PROSITE-ProRule annotation

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

GeneTreeiENSGT00390000017948.
HOGENOMiHOG000255206.
InParanoidiP00163.
KOiK00412.
OMAiPEHIVPE.
OrthoDBiEOG092C2QFL.

Family and domain databases

CDDicd00284. Cytochrome_b_N. 1 hit.
Gene3Di1.20.810.10. 1 hit.
InterProiIPR005798. Cyt_b/b6_C.
IPR005797. Cyt_b/b6_N.
IPR027387. Cytb/b6-like.
IPR030689. Cytochrome_b.
IPR016174. Di-haem_cyt_TM.
[Graphical view]
PfamiPF00032. Cytochrom_B_C. 1 hit.
PF00033. Cytochrome_B. 1 hit.
[Graphical view]
PIRSFiPIRSF038885. COB. 1 hit.
SUPFAMiSSF81342. SSF81342. 1 hit.
SSF81648. SSF81648. 1 hit.
PROSITEiPS51003. CYTB_CTER. 1 hit.
PS51002. CYTB_NTER. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P00163-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MAFRKSNVYL SLVNSYIIDS PQPSSINYWW NMGSLLGLCL VIQIVTGIFM
60 70 80 90 100
AMHYSSNIEL AFSSVEHIMR DVHNGYILRY LHANGASFFF MVMFMHMAKG
110 120 130 140 150
LYYGSYRSPR VTLWNVGVII FILTIATAFL GYCCVYGQMS HWGATVITNL
160 170 180 190 200
FSAIPFVGND IVSWLWGGFS VSNPTIQRFF ALHYLVPFII AAMVIMHLMA
210 220 230 240 250
LHIHGSSNPL GITGNLDRIP MHSYFIFKDL VTVFLFMLIL ALFVFYSPNT
260 270 280 290 300
LGHPDNYIPG NPLVTPASIV PEWYLLPFYA ILRSIPDKLL GVITMFAAIL
310 320 330 340 350
VLLVLPFTDR SVVRGNTFKV LSKFFFFIFV FNFVLLGQIG ACHVEVPYVL
360 370 380
MGQIATFIYF AYFLIIVPVI STIENVLFYI GRVNK
Length:385
Mass (Da):43,656
Last modified:April 23, 2003 - v3
Checksum:i1B1B1616BBC2A798
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti122I → T in CAA58861 (PubMed:7737175).Curated1
Sequence conflicti122I → T in AAA32151 (PubMed:7004642).Curated1
Sequence conflicti269I → ID in CAA24073 (PubMed:6253454).Curated1
Sequence conflicti269I → ID no nucleotide entry (PubMed:6383504).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural varianti131G → S in mutant W7 which is respiratory deficient. 1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
V00696 Genomic DNA. Translation: CAA24073.2. Sequence problems.
X84042 mRNA. Translation: CAA58861.1.
KP263414 Genomic DNA. Translation: AIZ98890.1.
J01473, J01472 Genomic DNA. Translation: AAA32151.2.
J01475, J01474 Genomic DNA. Translation: AAA32152.2.
PIRiA00159. CBBY.
S78660.
RefSeqiNP_009315.1. NC_001224.1.

Genome annotation databases

EnsemblFungiiQ0105; Q0105; Q0105.
GeneIDi854583.
KEGGisce:Q0105.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
V00696 Genomic DNA. Translation: CAA24073.2. Sequence problems.
X84042 mRNA. Translation: CAA58861.1.
KP263414 Genomic DNA. Translation: AIZ98890.1.
J01473, J01472 Genomic DNA. Translation: AAA32151.2.
J01475, J01474 Genomic DNA. Translation: AAA32152.2.
PIRiA00159. CBBY.
S78660.
RefSeqiNP_009315.1. NC_001224.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1EZVX-ray2.30C1-385[»]
1KB9X-ray2.30C1-385[»]
1KYOX-ray2.97C/N1-385[»]
1P84X-ray2.50C1-385[»]
2IBZX-ray2.30C1-385[»]
3CX5X-ray1.90C/N1-385[»]
3CXHX-ray2.50C/N1-385[»]
4PD4X-ray3.04C1-385[»]
ProteinModelPortaliP00163.
SMRiP00163.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi34779. 30 interactors.
IntActiP00163. 2 interactors.
MINTiMINT-4981526.

Protein family/group databases

TCDBi3.D.3.3.1. the proton-translocating quinol:cytochrome c reductase (qcr) superfamily.

Proteomic databases

PRIDEiP00163.
TopDownProteomicsiP00163.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblFungiiQ0105; Q0105; Q0105.
GeneIDi854583.
KEGGisce:Q0105.

Organism-specific databases

EuPathDBiFungiDB:Q0105.
SGDiS000007270. COB.

Phylogenomic databases

GeneTreeiENSGT00390000017948.
HOGENOMiHOG000255206.
InParanoidiP00163.
KOiK00412.
OMAiPEHIVPE.
OrthoDBiEOG092C2QFL.

Enzyme and pathway databases

BioCyciYEAST:Q0105-MONOMER.

Miscellaneous databases

EvolutionaryTraceiP00163.
PROiP00163.

Family and domain databases

CDDicd00284. Cytochrome_b_N. 1 hit.
Gene3Di1.20.810.10. 1 hit.
InterProiIPR005798. Cyt_b/b6_C.
IPR005797. Cyt_b/b6_N.
IPR027387. Cytb/b6-like.
IPR030689. Cytochrome_b.
IPR016174. Di-haem_cyt_TM.
[Graphical view]
PfamiPF00032. Cytochrom_B_C. 1 hit.
PF00033. Cytochrome_B. 1 hit.
[Graphical view]
PIRSFiPIRSF038885. COB. 1 hit.
SUPFAMiSSF81342. SSF81342. 1 hit.
SSF81648. SSF81648. 1 hit.
PROSITEiPS51003. CYTB_CTER. 1 hit.
PS51002. CYTB_NTER. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiCYB_YEAST
AccessioniPrimary (citable) accession number: P00163
Secondary accession number(s): A0A0A7NYK0
, Q35802, Q35807, Q36301, Q9ZZW9
Entry historyi
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: April 23, 2003
Last modified: November 2, 2016
This is version 155 of the entry and version 3 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programFungal Protein Annotation Program

Miscellaneousi

Miscellaneous

Heme 1 (or BL or b562) is low-potential and absorbs at about 562 nm, and heme 2 (or BH or b566) is high-potential and absorbs at about 566 nm.By similarity

Caution

The protein contains only eight transmembrane helices, not nine as predicted by bioinformatics tools.2 Publications

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
  3. Yeast
    Yeast (Saccharomyces cerevisiae): entries, gene names and cross-references to SGD

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.