Abstract
HtrA family proteins play a central role in protein quality control in the bacterial periplasmic space. DegQ-like proteases, a group of bacterial HtrA proteins, are characterized by a short LA loop as compared with DegP-like proteases, and are found in many bacterial species. As a representative of the DegQ-like proteases, we report that Escherichia coli DegQ exists in vivo primarily as a trimer (substrate-free) or dodecamer (substrate-containing). Biochemical analysis of DegQ dodecamers revealed that the major copurified protein substrate is OmpA. Importantly, wild-type DegQ exhibited a much lower proteolytic activity, and thus higher chaperone-like activity, than DegP. Furthermore, using cryo-electron microscopy we determined high-resolution structures of DegQ 12- and 24-mers in the presence of substrate, thus revealing the structural mechanism by which DegQ moderates its proteolytic activity.
Original language | English (US) |
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Pages (from-to) | 1328-1337 |
Number of pages | 10 |
Journal | Structure |
Volume | 19 |
Issue number | 9 |
DOIs | |
State | Published - Sep 7 2011 |
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology