College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea; Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, 06974, Republic of Korea.
Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang, 790-784, Republic of Korea.
Biochem Biophys Res Commun. 2023 Dec 25;688:149175. doi: 10.1016/j.bbrc.2023.149175. Epub 2023 Nov 4.
Protein quality control mechanisms are essential for maintaining cellular integrity, and the HtrA family of serine proteases plays a crucial role in handling folding stress in prokaryotic periplasm. Escherichia coli harbors three HtrA members, namely, DegS, DegP, and DegQ, which share a common domain structure. MucD, a putative HtrA family member that resembles DegP, is involved in alginate biosynthesis regulation and the stress response. Pseudomonas syringae causes plant diseases and opportunistic infections in humans. This study presents the high-resolution structure of MucD from Pseudomonas syringae (psMucD), revealing its composition as a typical HtrA family serine protease with protease and PDZ domains. Its findings suggest that psMucD containing one PDZ domain is a trimer in solution, and psMucD trimerization is mediated by its N-terminal loop. Sequence and structural analyses revealed similarities and differences with other HtrA family members. Additionally, this study provides a model of psMucD's catalytic process, comparing it with other members of the HtrA family of serine proteases.
蛋白质质量控制机制对于维持细胞完整性至关重要，而 HtrA 家族丝氨酸蛋白酶在处理原核周质中的折叠应激方面起着关键作用。大肠杆菌含有三种 HtrA 成员，即 DegS、DegP 和 DegQ，它们具有共同的结构域。MucD，一种类似于 DegP 的假定 HtrA 家族成员，参与了岩藻聚糖生物合成的调节和应激反应。丁香假单胞菌会引起植物疾病和人类机会性感染。本研究展示了来自丁香假单胞菌的 MucD（psMucD）的高分辨率结构，揭示了其作为一种典型的 HtrA 家族丝氨酸蛋白酶的组成，具有蛋白酶和 PDZ 结构域。研究结果表明，含有一个 PDZ 结构域的 psMucD 在溶液中是三聚体，而 psMucD 的三聚化是由其 N 端环介导的。序列和结构分析揭示了与其他 HtrA 家族成员的相似性和差异。此外，本研究还提供了 psMucD 催化过程的模型，将其与其他 HtrA 家族丝氨酸蛋白酶进行了比较。
