Allostery is an intrinsic property of the protease domain of DegS: implications for enzyme function and evolution.

ABSTRACT: DegS is a periplasmic Escherichia coli protease, which functions as a trimer to catalyze the initial rate-limiting step in a proteolytic cascade that ultimately activates transcription of stress response genes in the cytoplasm. Each DegS subunit consists of a protease domain and a PDZ domain. During protein folding stress, DegS is allosterically activated by peptides exposed in misfolded outer membrane porins, which bind to the PDZ domain and stabilize the active protease. It is not known whether allostery is conferred by the PDZ domains or is an intrinsic feature of the trimeric protease domain. Here, we demonstrate that free DegS(ΔPDZ) equilibrates between active and inactive trimers with the latter species predominating. Substrate binding stabilizes active DegS(ΔPDZ) in a positively coo

SUBMITTER: Sohn J 

PROVIDER: S-EPMC2962503 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature