Complex: Mitochondrial respiratory chain complex III
Macromolecular complex annotations are imported from the Complex Portal. These annotations have been derived from physical molecular interaction evidence extracted from the literature and cross-referenced in the entry, or by curator inference from information on homologs in closely related species or by inference from scientific background.
- Curated by
- IntAct
- ComplexAc
- CPX-567
- Systematic Name
- CYT1:COB:COR1:QCR2:QCR6:QCR7:QCR8:QCR9:QCR10:RIP1
- SGD ID
- SGD:S000218028
- Aliases
- Cyt bc1 complex ; Mitochondrial electron transport complex III ; Q-cytochrome c oxidoreductase ; QCR ; QH2:cytochrome c oxidoreductase ; Ubiquinol-cytochrome c reductase complex ; b6/f complex ; bc1 complex ; coQH2-cytochrome c oxidoreductase ; coenzyme Q-cytochrome c reductase ; coenzyme QH2-cytochrome c reductase ; complex III ; complex III (mitochondrial electron transport) ; cyt bc1 ; cytochrome b-c1 complex ; cytochrome b-c2 complex ; cytochrome bc1 complex ; dihydrocoenzyme Q-cytochrome c reductase ; f-b6 complex ; hydroubiquinone c2 oxidoreductase ; plastoquinol-plastocyanin oxidoreductase ; quinol cyt. c oxidoreductase (bc1) ; quinol-cytochrome c oxidoreductase complex ; reduced coenzyme Q-cytochrome c reductase ; reduced ubiquinone-cytochrome c oxidoreductase ; reduced ubiquinone-cytochrome c reductase ; respiratory complex III ; ubihydroquinol:cytochrome c oxidoreductase ; ubiquinol-cytochrome c oxidoreductase ; ubiquinol-cytochrome c reductase ; ubiquinol-cytochrome c reductase complex ; ubiquinol-cytochrome c-2 oxidoreductase ; ubiquinol-cytochrome c1 oxidoreductase ; ubiquinol-cytochrome c2 reductase ; ubiquinol:cytochrome c reductase ; ubiquinol:ferricytochrome c oxidoreductase ; ubiquinone-cytochrome b-c1 oxidoreductase ; ubiquinone-cytochrome c oxidoreductase ; ubiquinone-cytochrome c reductase
- Description
- Key role in aerobic respiration, in which mitochondrial enzymes accept electrons from electron carriers reduced in glycolysis and the tricarboxylic acid cycle. Ubiquinol-cytochrome c reductase pumps protons into the intermembrane space, creating an electrochemical gradient. This is achieved by oxidizing ubiquinol (ubihydroquinone) which reacts from the membrane phase, reducing cytochrome c in the intermembrane space, and using the free energy change to transport H+ ions across the membrane from the matrix to the inter membrane space. Quinol oxidation occurs in a bifurcated reaction, in which one electron is transferred to a high potential chain and the other to a low potential chain. The high potential chain, consisting of the iron sulfur protein, cyt c1 and cyt c2, transfers the first electron from quinol to an acceptor (cytochrome oxidase). The low potential chain consists of two cyt b hemes, which serve as a pathway through which electrons are transferred across the coupling membrane.
Complex Diagram
This diagram displays the protein subunits (blue) of the complex and how they interact with each other. Interactions with other relevant participants such as small molecules (purple), sub-complexes (yellow), and other subunits (red) are also shown. If a participant appears in the diagram with no lines connected to it, then its specific interactions with other participants are currently unknown.
Subunits
This table lists all participants of the complex (proteins, small molecules, nucleic acids, etc.) and their respective stoichiometry. A brief description is also provided for each participant in the table.
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| Subunit | Description | Stoichiometry |
|---|
Gene Ontology
Gene Ontology (GO) terms that describe the function of a complex, the biological process in which it participates, or its cellular location. Click on a term for its definition and other objects annotated to that term.
- Molecular Function
-
- enables electron transfer activity (IDA)
- enables ubiquinol-cytochrome-c reductase activity (IDA)
- Biological Process
-
- involved in cellular respiration (IDA)
- involved in mitochondrial electron transport, ubiquinol to cytochrome c (IDA)
- Cellular Component
-
- located in integral component of mitochondrial inner membrane (IDA)
- located in mitochondrial inner membrane (IDA)
Shared Annotations
This diagram displays Gene Ontology terms (green) and subunits (blue) that are shared between the given macromolecular complex (black) and other yeast complexes (yellow). The shared GO terms or subunits can be visualized separately using the radio button at the bottom of the graph. Note: No diagram is shown ("No shared annotations") if there are less than 2 shared annotations (either GO terms or subunits of other complexes) between this complex and any other complexes.
References
List of references used specifically to curate the information on this page.
- Das J (2006) The role of mitochondrial respiration in physiological and evolutionary adaptation. Bioessays 28(9):890-901 PMID: 16937356
- Saraste M (1999) Oxidative phosphorylation at the fin de siècle. Science 283(5407):1488-93 PMID: 10066163
Resources
IntAct | ModelArchive | PDB:1P84 | PDB:3CX5 | PDB:3CXH ... Show all Show fewer