A mitochondrial chaperonin: genetic, biochemical, and molecular characteristics.

Mitochondria contain a matrix-localized protein complex composed of subunits homologous to the E.coli protein groEL. As with groEL in E.coli, the nuclear gene coding for the mitochondrial protein is essential for cell survival and the accumulation of the protein is elevated at heat shock-inducing temperatures. Biochemical analyses of wild type and mutant yeast strains have shown that this protein, hsp60, is required for the correct folding and assembly of newly imported, mitochondrially-targeted proteins. There is evidence suggesting a mandatory interaction between hsp60 and many imported, as well as mitochondrially-synthesized, proteins. The implications of these and other data are discussed.