Eslami Sara M, van der Donk Wilfred A
Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
ACS Bio Med Chem Au. 2023 Dec 13;4(1):20-36. doi: 10.1021/acsbiomedchemau.3c00059. eCollection 2024 Feb 21.
Ribosomally synthesized and post-translationally modified peptides (RiPPs) have received much attention in recent years because of their promising bioactivities and the portability of their biosynthetic pathways. Heterologous expression studies of RiPP biosynthetic enzymes identified by genome mining often leave a leader peptide on the final product to prevent toxicity to the host and to allow the attachment of a genetically encoded affinity purification tag. Removal of the leader peptide to produce the mature natural product is then carried out in vitro with either a commercial protease or a protease that fulfills this task in the producing organism. This review covers the advances in characterizing these latter cognate proteases from bacterial RiPPs and their utility as sequence-dependent proteases. The strategies employed for leader peptide removal have been shown to be remarkably diverse. They include one-step removal by a single protease, two-step removal by two dedicated proteases, and endoproteinase activity followed by aminopeptidase activity by the same protease. Similarly, the localization of the proteolytic step varies from cytoplasmic cleavage to leader peptide removal during secretion to extracellular leader peptide removal. Finally, substrate recognition ranges from highly sequence specific with respect to the leader and/or modified core peptide to nonsequence specific mechanisms.
核糖体合成及翻译后修饰肽（RiPPs）近年来备受关注，因其具有潜在的生物活性以及生物合成途径的可移植性。通过基因组挖掘鉴定出的RiPP生物合成酶的异源表达研究，通常会在最终产物上保留一个前导肽，以防止对宿主产生毒性，并允许连接一个基因编码的亲和纯化标签。随后，使用商业蛋白酶或在产生生物体中执行此任务的蛋白酶在体外去除前导肽以产生成熟的天然产物。本综述涵盖了从细菌RiPPs中表征这些后源同源蛋白酶的进展及其作为序列依赖性蛋白酶的用途。已证明用于去除前导肽的策略非常多样。它们包括由单一蛋白酶一步去除、由两种专用蛋白酶两步去除，以及由同一蛋白酶先进行内切蛋白酶活性然后进行氨肽酶活性。同样，蛋白水解步骤的定位从细胞质裂解到分泌过程中前导肽的去除，再到细胞外前导肽的去除。最后，底物识别范围从对前导肽和/或修饰的核心肽具有高度序列特异性到非序列特异性机制。
