the kinetics of assembly of hsp60 subunits into the 2-heptameric rings takes two minutes. the subsequent protease-resistant hsp60 is formed in a half-time of 5–10 minutes. this rapid synthesis indicates that there is an atp-dependent interaction where the formed hsp60 complex stabilizes the intermediate of the hsp60 assembly complex, effectively serving as a catalyst. the necessity of preexisting hsp60 in order to synthesize additional hsp60 molecules supports the endosymbiotic theory of the origin of mitochondria. there must have been a rudimentary prokaryotic homologous protein that was capable of similar self-assembly.