The ATPase activity of chaperonin GroEL is highly stimulated at elevated temperatures

The chaperonin GroEL is a heat-shock protein that stabilizes folding intermediates by forming binary complexes. The release of bound polypeptides as active proteins requires ATP hydrolysis by GroEL. The ability of GroEL to support the folding of urea-unfolded rhodanese and to hydrolyze ATP was investigated at high temperatures. We found that the chaperonin-mediated folding of rhodanese and the ATPase activity of GroEL are temperature dependent. The GroEL ATPase activity, however, increases very strongly over the range of temperatures that is physiologically relevant for Escherichia coli growth. Further, GroES partially suppresses the GroEL ATPase activity in the same temperature range.