Microbiology, Faculty of Biology, Zentrum für Medizinische Biotechnologie (ZMB) , Universität Duisburg-Essen , Universitätsstr. 2 , 45117 Essen , Germany.
Max-Planck-Institute of Molecular Physiology , Otto-Hahn-Str. 11 , 44227 Dortmund , Germany.
ACS Chem Biol. 2018 May 18;13(5):1307-1312. doi: 10.1021/acschembio.8b00101. Epub 2018 Apr 16.
Covalent modifications of nonactive site lysine residues by small molecule probes has recently evolved into an important strategy for interrogating biological systems. Here, we report the discovery of a class of bioreactive compounds that covalently modify lysine residues in DegS, the rate limiting protease of the essential bacterial outer membrane stress response pathway. These modifications lead to an allosteric activation and allow the identification of novel residues involved in the allosteric activation circuit. These findings were validated by structural analyses via X-ray crystallography and cell-based reporter systems. We anticipate that our findings are not only relevant for a deeper understanding of the structural basis of allosteric activation in DegS and other HtrA serine proteases but also pinpoint an alternative use of covalent small molecules for probing essential biochemical mechanisms.
近年来，通过小分子探针对非活性位点赖氨酸残基的共价修饰已发展成为研究生物系统的重要策略。在这里，我们报告了一类生物反应性化合物的发现，这些化合物可使细菌外膜应激反应途径中必需的限速蛋白酶 DegS 中的赖氨酸残基发生共价修饰。这些修饰导致变构激活，并允许鉴定参与变构激活回路的新残基。这些发现通过 X 射线晶体学和基于细胞的报告系统的结构分析得到了验证。我们预计，我们的发现不仅与深入了解 DegS 和其他 HtrA 丝氨酸蛋白酶的变构激活的结构基础有关，而且还指出了使用共价小分子探测基本生化机制的另一种用途。
