The Legionella HtrA homologue DegQ is a self-compartmentizing protease that forms large 12-meric assemblies.

ABSTRACT: Proteases of the HtrA family are key factors dealing with folding stress in the periplasmatic compartment of prokaryotes. In Escherichia coli, the well-characterized HtrA family members DegS and DegP counteract the accumulation of unfolded outer-membrane proteins under stress conditions. Whereas DegS serves as a folding-stress sensor, DegP is a chaperone-protease facilitating refolding or degradation of defective outer-membrane proteins. Here, we report the 2.15-Å-resolution crystal structure of the second major chaperone-protease of the periplasm, DegQ from Legionella fallonii. DegQ assembles into large, cage-like 12-mers that form independently of unfolded substrate proteins. We provide evidence that 12-mer formation is essential for the degradation of substrate proteins but not for the

SUBMITTER: Wrase R 

PROVIDER: S-EPMC3127897 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature