摘要
毒素-抗毒素(toxin-antitoxin,TA)系统是一种广泛存在于细菌、古细菌和原噬菌体染色体和质粒的遗传元件。TA通常包含一个能够抑制细菌生长的毒素和一个能够中和其毒性的抗毒素。自20世纪80年代发现首个TA系统(Ccd B/Ccd A)以来,TA被证明几乎存在于所有已经测序的微生物,在维持质粒稳定性和抗噬菌体等方面具有重要作用。目前,TA被分为Ⅰ-Ⅷ型,其中Ⅱ型TA的研究最为广泛。HipBA是一个典型的Ⅱ型TA,大肠杆菌HipBA中毒素HipA是一种丝/苏氨酸激酶,通过磷酸化细菌的谷氨酰tRNA合成酶GltX,抑制蛋白质翻译过程,其毒性可以被抗毒素HipB特异性中和。最近研究发现,与大肠杆菌HipA同源的蛋白质广泛存在于微生物,它们与同一操纵子的基因共同组成潜在的新颖的TA,其中HipBST已被实验证实。HipBST中毒素HipT和抗毒素HipS分别与大肠杆菌HipA的C端和N端具有相似性,但其中和机制以及毒素的底物不同于大肠杆菌毒素HipA。本文总结了最近发现的特殊的TA,特别是对广泛存在于原核生物的HipBST的中和机制进行概述。
Toxin-antitoxin system(TA)is a genetic element widely found in chromosomes and plasmids of bacteria,archaea and prophages.TA usually consists a toxin that inhibits the growth of bacteria and an antitoxin that neutralizes its toxicity.Since the discovery of the first CcdB/CcdA TA in the 1980s,TA has been proved to exist in almost all sequenced microorganisms and plays an important role in maintaining plasmid stability,anti-phage and promoting biofilm formation.At present,TA is divided into type IVIII,among which type IITA is the most widely studied.HipBA is a type II TA.The toxin HipA in Escherichia coli HipBA is a serine/threonine kinase,which inhibits protein translation by phosphorylating bacterial Glutamyl tRNA synthetase(GltX),and its toxicity can be specifically neutralized by HipB.Recently,it has been found that Escherichia coli HipA homologous proteins exist widely in microorganisms,and they form a potential novel TA with genes of the same promoter,in which HipBST has been confirmed by experiments.The toxin HipT and the antitoxin HipS in this TA are similar to the C-terminal and N-terminal of E.coli HipA respectively,and the neutralization mechanism and the substrate of the toxin are different from that of E.coli toxin HipA.This study summarizes the recent discovery of special TA,especially the neutralization mechanism of HipBST which widely exists in prokaryotes.
作者
黄志杰
欧阳松应
甄向凯
HUANG Zhi-Jie;OUYANG Song-Ying;ZHEN Xiang-Kai(FJNU Biomedical Research Center of South,Fuzhou 350117,China;College of Life Sciences,Fujian Normal University,Fuzhou 350117,China)
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2023年第9期1247-1256,共10页
Chinese Journal of Biochemistry and Molecular Biology
基金
国家自然科学基金(No.32170045,82172287)资助。
