Send to

Choose Destination
Hum Mol Genet. 2003 Feb 1;12(3):329-39.

An intragenic suppressor in the cytochrome c oxidase I gene of mouse mitochondrial DNA.

Author information

Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.


We report here the identification of a cell line containing single and double missense mutations in cytochrome c oxidase (COX) subunit I gene of mouse mitochondrial DNA. When present in homoplasmy, the single mutant displays a normal complex IV assembly but a significantly reduced COX activity, while the double mutant almost completely compensates the functional defect of the first mutation. We discuss the potential structural consequences of those mutations based on the modeled structure of mouse complex IV. Based on genetic, biochemical and molecular analyses of cultured mouse cells we infer that: (i) deleterious mutations can arise and become predominant; (ii) cultured cells can maintain several mtDNA haplotypes at stable frequencies; (iii) the respiratory chain has little spare COX capacity; and (iv) the size of a cavity in the vicinity of Val421 in CO I of animal COX may affect the function of the enzyme.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center