毒性分子-抗毒性分子系统的生物学作用研究进展

毒性分子-抗毒性分子系统(toxin-antitoxin systems,TA systems)被发现广泛存在于细菌染色体、质粒以及古细菌基因组中。TA系统是由2个基因组成的操纵子,这2个基因分别编码稳定的毒性分子和不稳定的抗毒性分子。毒性分子总是蛋白质,抗毒性分子可能是蛋白质或RNA。因此,根据抗毒性分子的性质和作用方式的不同可将TA系统家族分为5种类型。Ⅰ型和Ⅲ型的抗毒性分子是RNA,能抑制毒性分子的合成或者与其隔离;II、IV和V型的抗毒性分子是蛋白质,能隔离、平衡毒性分子作用或抑制其合成。TA系统具有多种生物学功能。目前研究表明,TA系统可能在细菌应激应答、程序化细胞死亡、多重耐药的形成、防止DNA入侵、稳定大基因组片段等方面有重要的作用。

Advances in Biological Function of Toxin-Antitoxin Molecular Systems

Toxin-antitoxin systems (TA systems) extensively exist in bacterial chromosomes and plasmids as well as in archaic genomes. TA systems is an operon consisting of two genes, they are respectively toxin molecule of stably encoded and anti toxin molecule of unstably encoded. Toxin molecule is always protein, while antitoxin molecule may be protein or RNA. Therefore, currently TA systems family can be divided into five different types. Antitoxin molecule of type I and type III is RNA, it can inhibit the synthesis of toxin molecule or isolate toxin molecule. Antitoxin molecule of type II, IV, and V is protein, it can isolate, balance the role of toxin molecule or inhibit its synthesis. TA systems possess multiple biological functions. Recent studies suggested that TA systems might play important role and have involved in the cell stress response, programmed cell death, the form of multidrug resistance, prevention from DNA invasion, as well as stabilization of large genomic fragments and other aspects.