From Microstates to Macrostates in the Conformational Dynamics of GroEL: A Single-Molecule Forster Resonance Energy Transfer Study.

ABSTRACT: The chaperonin GroEL is a multisubunit molecular machine that assists in protein folding in the Escherichia coli cytosol. Past studies have shown that GroEL undergoes large allosteric conformational changes during its reaction cycle. Here, we report single-molecule Förster resonance energy transfer measurements that directly probe the conformational transitions of one subunit within GroEL and its single-ring variant under equilibrium conditions. We find that four microstates span the conformational manifold of the protein and interconvert on the submillisecond time scale. A unique set of relative populations of these microstates, termed a macrostate, is obtained by varying solution conditions, e.g., adding different nucleotides or the cochaperone GroES. Strikingly, ATP titration stu

SUBMITTER: Liebermann DG 

PROVIDER: S-EPMC10388350 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature