Arabinose Alters Both Local and Distal H-D Exchange Rates in the Escherichia coli AraC Transcriptional Regulator.

ABSTRACT: In the absence of arabinose, the dimeric Escherichia coli regulatory protein of the l-arabinose operon, AraC, represses expression by looping the DNA between distant half-sites. Binding of arabinose to the dimerization domains forces AraC to preferentially bind two adjacent DNA half-sites, which stimulates RNA polymerase transcription of the araBAD catabolism genes. Prior genetic and biochemical studies hypothesized that arabinose allosterically induces a helix-coil transition of a linker between the dimerization and DNA binding domains that switches the AraC conformation to an inducing state [Brown, M. J., and Schleif, R. F. (2019) Biochemistry, preceding paper in this issue (DOI: 10.1021/acs.biochem.9b00234)]. To test this hypothesis, hydrogen-deuterium exchange mass spectrometry was uti

SUBMITTER: Tischer A 

PROVIDER: S-EPMC11747938 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature