Time-resolved neutron scattering provides new insight into protein substrate processing by a AAA+ unfoldase.

ABSTRACT: We present a combination of small-angle neutron scattering, deuterium labelling and contrast variation, temperature activation and fluorescence spectroscopy as a novel approach to obtain time-resolved, structural data individually from macromolecular complexes and their substrates during active biochemical reactions. The approach allowed us to monitor the mechanical unfolding of a green fluorescent protein model substrate by the archaeal AAA+ PAN unfoldase on the sub-minute time scale. Concomitant with the unfolding of its substrate, the PAN complex underwent an energy-dependent transition from a relaxed to a contracted conformation, followed by a slower expansion to its initial state at the end of the reaction. The results support a model in which AAA ATPases unfold their substrates in a

SUBMITTER: Ibrahim Z 

PROVIDER: S-EPMC5244417 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature