Substrate binding stabilizes a pre-translocation intermediate in the ATP-binding cassette transport protein MsbA.

ABSTRACT: ATP-binding cassette (ABC) transporters belong to one of the largest protein superfamilies that expands from prokaryotes to man. Recent x-ray crystal structures of bacterial and mammalian ABC exporters suggest a common alternating access mechanism of substrate transport, which has also been biochemically substantiated. However, the current model does not yet explain the coupling between substrate binding and ATP hydrolysis that underlies ATP-dependent substrate transport. In our studies on the homodimeric multidrug/lipid A ABC exporter MsbA from Escherichia coli, we performed cysteine cross-linking, fluorescence energy transfer, and cysteine accessibility studies on two reporter positions, near the nucleotide-binding domains and in the membrane domains, for transporter embedded in a biolog

SUBMITTER: Doshi R 

PROVIDER: S-EPMC3724623 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature