An active role for a structured B-linker in effector control of the sigma54-dependent regulator DmpR.

ABSTRACT: The activities of many prokaryotic sigma54-dependent transcriptional activators are controlled by the N-terminal A-domain of the protein, which is linked to the central transcriptional activation domain via a short B-linker. It used to be thought that these B-linkers simply serve as flexible tethers. Here we show that the B-linker of the aromatic-responsive regulator DmpR and many other regulators of the family contain signature heptad repeats with regularly spaced hydrophobic amino acids. Mutant analysis of this region of DmpR demonstrates that B-linker function is dependent on the heptad repeats and is critical for activation of the protein by aromatic effectors. The phenotypes of DmpR mutants refute the existing model that the level of ATPase activity directly controls the level of tran

SUBMITTER: O'Neill E 

PROVIDER: S-EPMC145425 | biostudies-literature | 2001 Feb

REPOSITORIES: biostudies-literature