Q89AA4 · CYOB_BUCBP
- ProteinCytochrome bo(3) ubiquinol oxidase subunit 1
- GenecyoB
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids659 (go to sequence)
- Protein existenceInferred from homology
- Annotation score4/5
Function
function
Cytochrome bo3 ubiquinol oxidase is the terminal enzyme in the aerobic respiratory chain. Catalyzes the four-electron reduction of O2 to water, using a ubiquinol as a membrane soluble electron donor for molecular oxygen reduction. Has proton pump activity across the membrane in addition to electron transfer, pumping 2 protons/electron and generating a proton motive force. All the redox centers of this enzyme complex are located within the largest subunit, subunit I. Protons are probably pumped via D- and K- channels found in this subunit.
Miscellaneous
Ubiquinol oxidase catalyzes the terminal step in the electron transport chain.
Catalytic activity
- 2 a ubiquinol + n H+(in) + O2 = 2 a ubiquinone + n H+(out) + 2 H2O
2 a ubiquinol RHEA-COMP:9566 + n H+ (in)CHEBI:15378+ CHEBI:15379 = 2 a ubiquinone RHEA-COMP:9565 + n H+ (out)CHEBI:15378+ 2 CHEBI:15377
Cofactor
Protein has several cofactor binding sites:
Note: Binds 1 copper B ion per subunit.
Note: Binds 1 low-spin heme b per subunit.
Note: Binds 1 high-spin heme o per subunit, also named heme o3.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 71 | a ubiquinone (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 75 | a ubiquinone (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 101 | a ubiquinone (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 109 | Fe (UniProtKB | ChEBI) of heme b (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 173 | heme b (UniProtKB | ChEBI) | ||||
Sequence: W | ||||||
Binding site | 287 | Cu2+ (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 291 | Fe(II)-heme o (UniProtKB | ChEBI) | ||||
Sequence: Y | ||||||
Binding site | 336 | Cu2+ (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 337 | Cu2+ (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 414 | Fe(II)-heme o (UniProtKB | ChEBI) | ||||
Sequence: H | ||||||
Binding site | 422 | Fe (UniProtKB | ChEBI) of Fe(II)-heme o (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 424 | Fe (UniProtKB | ChEBI) of heme b (UniProtKB | ChEBI); axial binding residue | ||||
Sequence: H | ||||||
Binding site | 484 | heme b (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 485 | heme b (UniProtKB | ChEBI) | ||||
Sequence: R |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | plasma membrane | |
Cellular Component | respirasome | |
Molecular Function | cytochrome bo3 ubiquinol oxidase activity | |
Molecular Function | cytochrome-c oxidase activity | |
Molecular Function | heme binding | |
Molecular Function | metal ion binding | |
Molecular Function | oxidoreductase activity, acting on diphenols and related substances as donors, oxygen as acceptor | |
Biological Process | aerobic respiration | |
Biological Process | electron transport coupled proton transport | |
Biological Process | respiratory electron transport chain |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameCytochrome bo(3) ubiquinol oxidase subunit 1
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageBacteria > Pseudomonadota > Gammaproteobacteria > Enterobacterales > Erwiniaceae > Buchnera
Accessions
- Primary accessionQ89AA4
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Cell membrane ; Multi-pass membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-14 | Extracellular | ||||
Sequence: MFGKLSLNSIPYHD | ||||||
Transmembrane | 15-35 | Helical | ||||
Sequence: PIIMITCCVVILVFLVISIII | ||||||
Topological domain | 36-56 | Cytoplasmic | ||||
Sequence: TIAQKWQYLWNEWCCTVDHKK | ||||||
Transmembrane | 57-77 | Helical | ||||
Sequence: IAKMYIFLAFIMLFRGFADAI | ||||||
Topological domain | 78-109 | Extracellular | ||||
Sequence: MMRMQQFLVSSYHGNGTGFLPPHHYDQIFTAH | ||||||
Transmembrane | 110-130 | Helical | ||||
Sequence: GVIMIFFVAMPLVIGLMNFVV | ||||||
Topological domain | 131-148 | Cytoplasmic | ||||
Sequence: PLQIGSRDVAFPFLNNLS | ||||||
Transmembrane | 149-169 | Helical | ||||
Sequence: LWLTIFSALLMNVSLGIGEFA | ||||||
Topological domain | 170-192 | Extracellular | ||||
Sequence: QTGWLAYPPLSELQYSPGVGVDY | ||||||
Transmembrane | 193-213 | Helical | ||||
Sequence: WIWSLQISGIGTTLTAINFLV | ||||||
Topological domain | 214-235 | Cytoplasmic | ||||
Sequence: TIIKMRSSGMNWFKIPVFTWTS | ||||||
Transmembrane | 236-256 | Helical | ||||
Sequence: FCTNILIIASFPVLTVSLLLL | ||||||
Topological domain | 257-280 | Extracellular | ||||
Sequence: TLDRYLGFHFFTNDFGGNMMMYVN | ||||||
Transmembrane | 281-301 | Helical | ||||
Sequence: LIWIWGHPEVYILILPVFGIF | ||||||
Topological domain | 302-318 | Cytoplasmic | ||||
Sequence: SEVVATFSSKELFGYTS | ||||||
Transmembrane | 319-339 | Helical | ||||
Sequence: LIWATIVITILSFIVWLHHFF | ||||||
Topological domain | 340-350 | Extracellular | ||||
Sequence: TMGASANVNAF | ||||||
Transmembrane | 351-371 | Helical | ||||
Sequence: FGITTMIISIPTGVKIFNWLF | ||||||
Topological domain | 372-382 | Cytoplasmic | ||||
Sequence: TMYRGNVRINS | ||||||
Transmembrane | 383-403 | Helical | ||||
Sequence: IMLWTIGFLITFSIGGMAGVL | ||||||
Topological domain | 404-416 | Extracellular | ||||
Sequence: LSLPVIDFSLHNS | ||||||
Transmembrane | 417-437 | Helical | ||||
Sequence: LFLVAHFHNVIIGGVVFGCFA | ||||||
Topological domain | 438-459 | Cytoplasmic | ||||
Sequence: GITYWFPKLFGFMLSEKWGKRA | ||||||
Transmembrane | 460-480 | Helical | ||||
Sequence: FWCWFFGFFCAFMPLYALGLM | ||||||
Topological domain | 481-499 | Extracellular | ||||
Sequence: GMTRRLSQNINPQFHSMLT | ||||||
Transmembrane | 500-520 | Helical | ||||
Sequence: IAALGTILIFIGIVFQIIQIF | ||||||
Topological domain | 521-587 | Cytoplasmic | ||||
Sequence: VSIRDRNLNRDCSGDPWNGRTLEWSTTSPPPFYNFAVLPIVQFRDSFWESKKSFKSNKLPILYTSFH | ||||||
Transmembrane | 588-608 | Helical | ||||
Sequence: MPKNTKFGFLIGFFAFLLGFS | ||||||
Topological domain | 609 | Extracellular | ||||
Sequence: A | ||||||
Transmembrane | 610-630 | Helical | ||||
Sequence: VWYIFWLFFISFFVIIYLLVI | ||||||
Topological domain | 631-659 | Cytoplasmic | ||||
Sequence: KSLDTNCDYIISIEEIKEIEKCINIKKMD |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain, cross-link.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000183481 | 1-659 | Cytochrome bo3 ubiquinol oxidase subunit 1 | |||
Sequence: MFGKLSLNSIPYHDPIIMITCCVVILVFLVISIIITIAQKWQYLWNEWCCTVDHKKIAKMYIFLAFIMLFRGFADAIMMRMQQFLVSSYHGNGTGFLPPHHYDQIFTAHGVIMIFFVAMPLVIGLMNFVVPLQIGSRDVAFPFLNNLSLWLTIFSALLMNVSLGIGEFAQTGWLAYPPLSELQYSPGVGVDYWIWSLQISGIGTTLTAINFLVTIIKMRSSGMNWFKIPVFTWTSFCTNILIIASFPVLTVSLLLLTLDRYLGFHFFTNDFGGNMMMYVNLIWIWGHPEVYILILPVFGIFSEVVATFSSKELFGYTSLIWATIVITILSFIVWLHHFFTMGASANVNAFFGITTMIISIPTGVKIFNWLFTMYRGNVRINSIMLWTIGFLITFSIGGMAGVLLSLPVIDFSLHNSLFLVAHFHNVIIGGVVFGCFAGITYWFPKLFGFMLSEKWGKRAFWCWFFGFFCAFMPLYALGLMGMTRRLSQNINPQFHSMLTIAALGTILIFIGIVFQIIQIFVSIRDRNLNRDCSGDPWNGRTLEWSTTSPPPFYNFAVLPIVQFRDSFWESKKSFKSNKLPILYTSFHMPKNTKFGFLIGFFAFLLGFSAVWYIFWLFFISFFVIIYLLVIKSLDTNCDYIISIEEIKEIEKCINIKKMD | ||||||
Cross-link | 287↔291 | 1'-histidyl-3'-tyrosine (His-Tyr) | ||||
Sequence: HPEVY |
Interaction
Subunit
The cytochrome bo3 ubiquinol oxidase complex is a heterooctamer of two A chains, two B chains, two C chains and two D chains.
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length659
- Mass (Da)75,583
- Last updated2003-06-01 v1
- Checksum13DD8E19D4F5FC15
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AE016826 EMBL· GenBank· DDBJ | AAO27126.1 EMBL· GenBank· DDBJ | Genomic DNA |