Repetitive protein unfolding by the trans ring of the GroEL-GroES chaperonin complex stimulates folding.

ABSTRACT: A key constraint on the growth of most organisms is the slow and inefficient folding of many essential proteins. To deal with this problem, several diverse families of protein folding machines, known collectively as molecular chaperones, developed early in evolutionary history. The functional role and operational steps of these remarkably complex nanomachines remain subjects of active debate. Here we present evidence that, for the GroEL-GroES chaperonin system, the non-native substrate protein enters the folding cycle on the trans ring of the double-ring GroEL-ATP-GroES complex rather than the ADP-bound complex. The properties of this ATP complex are designed to ensure that non-native substrate protein binds first, followed by ATP and finally GroES. This binding order ensures efficient occ

SUBMITTER: Lin Z 

PROVIDER: S-EPMC3829408 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature