细菌核糖体的拯救机制

Mechanism of Ribosome Rescue in Bacteria

蛋白质翻译过程中,很多因素可能导致核糖体在mRNA上熄火,这对细胞的危害很大,因为这不仅占用了核糖体、氨基酸和tRNA,而且还可能产生有害的蛋白质.细菌进化出了多种核糖体拯救机制,释放熄火的核糖体,清除异常的mRNA,以规避毒害,如:①tmRNA·SmpB介导的拯救机制,又称为反式翻译介导的拯救机制;②ArfA(YhdL)介导的拯救机制;③YaeJ(ArfB)介导的拯救机制.这些机制对于细菌的生理和繁殖都非常重要,但却在真核生物进化过程中消失了,使这些机制有可能成为抗菌药物靶点.本文主要就细菌核糖体的拯救机制做一概述,并对这些机制的应用前景进行了展望.

Occasionally,during translation,ribosomes stall on mRNAs prior to the completion,this serious threat to the cells,as it not only sequesters the ribosomes,amino acids and tRNAs,but also potentially produces toxic polypeptides.The bacteria have evolved some rescue mechanisms to ensure efficient release of the stalled ribosomes and removal of the defective mRNAs to avoid toxicity： ① tmRNA·SmpB-mediated rescue pathways,or trans-translation-mediated rescue pathways;② ArfA（YhdL）-mediated rescue pathways;③YaeJ（ArfB）-mediated rescue pathways.These rescue pathways are important for both bacterial physiology and pathogenesis,but have been missed in the eukaryotes,so these may serve as promising targets for developing novel antibiotics.In this article,the mechanisms of bacteria ribosome rescue will be discussed,and the application perspective of these mechanisms will also be speculated.