3STI

Crystal structure of the protease domain of DegQ from Escherichia coli

3STI の概要

• エントリーDOI: 10.2210/pdb3sti/pdb
• 関連するPDBエントリー: 3STJ
• 分子名称: Protease degQ (1 entity in total)
• 機能のキーワード: serine protease, pdz domain, protease, chaperone, hydrolase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Periplasm: P39099
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 76970.34

構造登録者

Sawa, J.,Malet, H.,Krojer, T.,Canellas, F.,Ehrmann, M.,Clausen, T. (登録日: 2011-07-11, 公開日: 2011-07-27, 最終更新日: 2024-02-28)

主引用文献

Sawa, J.,Malet, H.,Krojer, T.,Canellas, F.,Ehrmann, M.,Clausen, T.
Molecular adaptation of the DegQ protease to exert protein quality control in the bacterial cell envelope.
J.Biol.Chem., 286:30680-30690, 2011

PubMed Abstract: To react to distinct stress situations and to prevent the accumulation of misfolded proteins, all cells employ a number of proteases and chaperones, which together set up an efficient protein quality control system. The functionality of proteins in the cell envelope of Escherichia coli is monitored by the HtrA proteases DegS, DegP, and DegQ. In contrast with DegP and DegS, the structure and function of DegQ has not been addressed in detail. Here, we show that substrate binding triggers the conversion of the resting DegQ hexamer into catalytically active 12- and 24-mers. Interestingly, substrate-induced oligomer reassembly and protease activation depends on the first PDZ domain but not on the second. Therefore, the regulatory mechanism originally identified in DegP should be a common feature of HtrA proteases, most of which encompass only a single PDZ domain. Using a DegQ mutant lacking the second PDZ domain, we determined the high resolution crystal structure of a dodecameric HtrA complex. The nearly identical domain orientation of protease and PDZ domains within 12- and 24-meric HtrA complexes reveals a conserved PDZ1 → L3 → LD/L1/L2 signaling cascade, in which loop L3 senses the repositioned PDZ1 domain of higher order, substrate-engaged particles and activates protease function. Furthermore, our in vitro and in vivo data imply a pH-related function of DegQ in the bacterial cell envelope.

PubMed: 21685389
DOI: 10.1074/jbc.M111.243832

実験手法

X-RAY DIFFRACTION (2.6 Å)