Direct substitution and assisted dissociation pathways for turning off transcription by a MerR-family metalloregulator.

ABSTRACT: Metalloregulators regulate transcription in response to metal ions. Many studies have provided insights into how transcription is activated upon metal binding by MerR-family metalloregulators. In contrast, how transcription is turned off after activation is unclear. Turning off transcription promptly is important, however, as the cells would not want to continue expressing metal resistance genes and thus waste energy after metal stress is relieved. Using single-molecule FRET measurements we studied the dynamic interactions of the copper efflux regulator (CueR), a Cu(+)-responsive MerR-family metalloregulator, with DNA. Besides quantifying its DNA binding and unbinding kinetics, we discovered that CueR spontaneously flips its binding orientation at the recognition site. CueR also has two di

SUBMITTER: Joshi CP 

PROVIDER: S-EPMC3458356 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature