COX9/YDL067C Summary Help

Standard Name COX9
Systematic Name YDL067C
Feature Type ORF, Verified
Description Subunit VIIa of cytochrome c oxidase (Complex IV); Complex IV is the terminal member of the mitochondrial inner membrane electron transport chain (1 and see Summary Paragraph)
Name Description Cytochrome c OXidase
Chromosomal Location
ChrIV:334396 to 334217 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All COX9 GO evidence and references
  View Computational GO annotations for COX9
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 7 genes
Classical genetics
reduction of function
Large-scale survey
72 total interaction(s) for 68 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 9
  • Affinity Capture-RNA: 2

Genetic Interactions
  • Dosage Lethality: 1
  • Negative Genetic: 43
  • Positive Genetic: 16
  • Synthetic Lethality: 1

Expression Summary
Length (a.a.) 59
Molecular Weight (Da) 6,963
Isoelectric Point (pI) 10.6
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrIV:334396 to 334217 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2004-02-11 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..180 334396..334217 2004-02-11 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000002225

Cytochrome c oxidase catalyzes the terminal step in the electron transport chain involved in cellular respiration. This multisubunit enzyme of the mitochondrial inner membrane, also known as Complex IV, is composed of three core subunits encoded by the mitochondrial genome (Cox1p, Cox2p, and Cox3p) and eight additional subunits encoded by nuclear genes (Cox4p, Cox5Ap or Cox5Bp, Cox6p, Cox7p, Cox8p, Cox9p, Cox12p, and Cox13p) (2, 3, 4). The phenotype of a mutation affecting any of the genes encoding cytochrome c oxidase subunits, or any of the multiple genes required for expression or assembly of the subunits (reviewed in 5), is a decrease or block in respiratory growth. The inability to respire is not lethal since S. cerevisiae can grow by fermentation, but nonrespiring cells grow more slowly than respiratory-competent cells even on glucose-containing medium, resulting in smaller colony size. Such mutations causing "petite" colonies were first described by Ephrussi and colleagues around 1950 (6).

Last updated: 2006-08-18 Contact SGD

References cited on this page View Complete Literature Guide for COX9
1) Wright RM, et al.  (1986) Characterization of COX9, the nuclear gene encoding the yeast mitochondrial protein cytochrome c oxidase subunit VIIa. Subunit VIIa lacks a leader peptide and is an essential component of the holoenzyme. J Biol Chem 261(36):17183-91
2) Taanman JW and Capaldi RA  (1992) Purification of yeast cytochrome c oxidase with a subunit composition resembling the mammalian enzyme. J Biol Chem 267(31):22481-5
3) Geier BM, et al.  (1995) Kinetic properties and ligand binding of the eleven-subunit cytochrome-c oxidase from Saccharomyces cerevisiae isolated with a novel large-scale purification method. Eur J Biochem 227(1-2):296-302
4) Cooper CE, et al.  (1991) Cytochrome c oxidase: structure, function, and membrane topology of the polypeptide subunits. Biochem Cell Biol 69(9):586-607
5) Herrmann JM and Funes S  (2005) Biogenesis of cytochrome oxidase-sophisticated assembly lines in the mitochondrial inner membrane. Gene 354():43-52
6) Ephrussi B and Slonimski PP  (1955) Subcellular units involved in the synthesis of respiratory enzymes in yeast. Nature 176(4495):1207-8