Structural basis for cAMP-mediated allosteric control of the catabolite activator protein.

ABSTRACT: The cAMP-mediated allosteric transition in the catabolite activator protein (CAP; also known as the cAMP receptor protein, CRP) is a textbook example of modulation of DNA-binding activity by small-molecule binding. Here we report the structure of CAP in the absence of cAMP, which, together with structures of CAP in the presence of cAMP, defines atomic details of the cAMP-mediated allosteric transition. The structural changes, and their relationship to cAMP binding and DNA binding, are remarkably clear and simple. Binding of cAMP results in a coil-to-helix transition that extends the coiled-coil dimerization interface of CAP by 3 turns of helix and concomitantly causes rotation, by approximately 60 degrees , and translation, by approximately 7 A, of the DNA-binding domains (DBDs) of CAP, po

SUBMITTER: Popovych N 

PROVIDER: S-EPMC2678429 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature