该团队报道了细菌核糖体与肽基tRNA复合物的结构和肽前释放状态的RFs。肽基转移酶中心未见水解水分子。相反，RFs诱导了肽基tRNA腺嘌呤76 （A76）核糖折叠体的重排，使2 '-OH定向到邻近的羰基上进行亲核攻击。这些发现提示了RFs介导的肽释放的催化机制，并为肽RFs催化结构域的普遍保守提供了结构基础。
据介绍，翻译终止在所有生物体中都是必不可少的，因为它确保了蛋白质的长度严格由它们的基因决定。这个普遍的过程是由肽释放因子（RFs）介导的，RFs识别停止密码子并催化核糖体上肽基转移RNA（肽基-tRNA）的水解，可能是通过激活水分子。
附：英文原文
Title: Mechanism of release factor–mediated peptidyl-tRNA hydrolysis on the ribosome
Author: Elena V. Aleksandrova, Egor A. Syroegin, Ritwika S. Basu, Alexander A. Vassilevski, Matthieu G. Gagnon, Yury S. Polikanov
Issue&Volume: 2025-06-19
Abstract: Translation termination is essential in all living organisms because it ensures that proteins have lengths strictly defined by their genes. This universal process is mediated by peptide release factors (RFs) that recognize stop codons and catalyze the hydrolysis of peptidyl transfer RNA (peptidyl-tRNA) on the ribosome, presumably by activating a water molecule. We report structures of the bacterial ribosome in complex with peptidyl-tRNA and RFs in the prepeptide release state. No hydrolytic water molecule was seen in the peptidyl transferase center. Instead, RFs induced rearrangements of the peptidyl-tRNA adenine 76 (A76) ribose pucker that orient the 2′-OH for the nucleophilic attack onto the neighboring carbonyl group. These findings suggest a catalytic mechanism of RF-mediated peptide release and provide a structural basis for the universal conservation of the catalytic domain in peptide RFs.
DOI: ads9030
Source: https://www.science.org/doi/10.1126/science.ads9030