A CHINESE-HAMSTER MUTANT-CELL LINE WITH A DEFECT IN THE INTEGRAL MEMBRANE-PROTEIN C-II-3 OF COMPLEX-II OF THE MITOCHONDRIAL ELECTRON-TRANSPORT CHAIN

In this study, a respiration-deficient Chinese hamster cell line with a defect in succinate dehydrogenase activity is shown to result from a single base change in a codon in the coding sequence for the membrane anchor protein C-II-3 (also referred to as QPs-1). A premature transl ation stop results in the truncation of 33 amino acids from the C term inus. Bovine cDNA encoding this peptide complements the mutation. Ther e is about 82% identity between these two mammalian proteins. The gene for C-II-3 was mapped on human chromosome 1, and because it is also f ound on minichromosomes characterized by our laboratory, we can locali ze it on the short arm within 1-2 megabases from the centromere.