Quorum-sensing agr mediates bacterial oxidation response via an intramolecular disulfide redox switch in the response regulator AgrA.

ABSTRACT: Oxidation sensing and quorum sensing significantly affect bacterial physiology and host-pathogen interactions. However, little attention has been paid to the cross-talk between these two seemingly orthogonal signaling pathways. Here we show that the quorum-sensing agr system has a built-in oxidation-sensing mechanism through an intramolecular disulfide switch possessed by the DNA-binding domain of the response regulator AgrA. Biochemical and mass spectrometric analysis revealed that oxidation induces the intracellular disulfide bond formation between Cys-199 and Cys-228, thus leading to dissociation of AgrA from DNA. Molecular dynamics (MD) simulations suggest that the disulfide bond formation generates a steric clash responsible for the abolished DNA binding of the oxidized AgrA. Mutagene

SUBMITTER: Sun F 

PROVIDER: S-EPMC3384213 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature