YcaO-mediated ATP-dependent peptidase activity in ribosomal peptide biosynthesis.
YcaO-mediated ATP-dependent peptidase activity in ribosomal peptide biosynthesis.
复制标题
核糖体肽生物合成中 YcaO 介导的 ATP 依赖性肽酶活性。
DOI：
10.1038/s41589-022-01141-0
复制
发表时间：
2023
影响因子：
14.8
通讯作者：
Nair,SatishK
中科院分区：
文献类型：
--
作者：
Zheng,Yiwu;Nair,SatishK
YcaO酶催化肽上的ATP依赖性翻译后修饰，包括（ox/thi）唑啉、硫代酰胺和/或脒部分的安装。在这里，我们表明，在生物合成的双-甲基恶唑生物碱muscoride A，YcaO酶MusD进行ATP依赖性的环化脱水和肽键裂解，这是一个前所未有的机制，这样的反应。YCaO催化的修饰被认为是通过骨架O-磷酸化中间体发生的，但这种机制仍然是推测性的。我们报告，据我们所知，第一次表征的酰基磷酸盐物种与骨架酰胺活化的拟议机制一致。MusD沿着生化分析的3.1倍分辨率低温电子显微镜结构允许鉴定能够进行肽切割反应的残基。生物信息学分析鉴定了可能部署双功能YcaO酶的其他氰基氧化菌素途径。我们的结构，突变和机制研究扩大了YcaO蛋白质催化的修饰范围，包括肽水解，并为催化多样性结果的统一机制提供证据。
YcaO enzymes catalyze ATP-dependent post-translation modifications on peptides, including the installation of (ox/thi)azoline, thioamide and/or amidine moieties. Here we demonstrate that, in the biosynthesis of the bis-methyloxazolic alkaloid muscoride A, the YcaO enzyme MusD carries out both ATP-dependent cyclodehydration and peptide bond cleavage, which is a mechanism unprecedented for such a reaction. YcaO-catalyzed modifications are proposed to occur through a backboneO-phosphorylated intermediate, but this mechanism remains speculative. We report, to our knowedge, the first characterization of an acyl-phosphate species consistent with the proposed mechanism for backbone amide activation. The 3.1-Å-resolution cryogenic electron microscopy structure of MusD along with biochemical analysis allow identification of residues that enable peptide cleavage reaction. Bioinformatics analysis identifies other cyanobactin pathways that may deploy bifunctional YcaO enzymes. Our structural, mutational and mechanistic studies expand the scope of modifications catalyzed by YcaO proteins to include peptide hydrolysis and provide evidence for a unifying mechanism for the catalytically diverse outcomes.