A single-ring mitochondrial chaperonin (Hsp60-Hsp10) can substitute for GroEL-GroES in vivo

Chaperonins participate in the facilitated folding of a variety of proteins in vivo. To see whether the same spectrum of target proteins can be produc tively folded by the double-ring prokaryotic chaperonin GroEL-GroES and its single-ring human mitochondrial homolog, Hsp60-Hsp10, we expressed the lat ter in an Escherichia coli strain engineered so that the groE operon is und er strict regulatory control. We found that expression of Hsp60-Hsp10 resto res viability to cells that no longer express GroEL-GroES, formally demonst rating that Hsp60-Hsp10 can carry out all essential in vivo functions of Gr oEL-GroES.