Evidence for close side-chain packing in an early protein folding intermediate previously assumed to be a molten globule.

ABSTRACT: The molten globule, a conformational ensemble with significant secondary structure but only loosely packed tertiary structure, has been suggested to be a ubiquitous intermediate in protein folding. However, it is difficult to assess the tertiary packing of transiently populated species to evaluate this hypothesis. Escherichia coli RNase H is known to populate an intermediate before the rate-limiting barrier to folding that has long been thought to be a molten globule. We investigated this hypothesis by making mimics of the intermediate that are the ground-state conformation at equilibrium, using two approaches: a truncation to generate a fragment mimic of the intermediate, and selective destabilization of the native state using point mutations. Spectroscopic characterization and the respon

SUBMITTER: Rosen LE 

PROVIDER: S-EPMC4205613 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature