Rawlings D E
Department of Microbiology, University of Stellenbosch, Matieland, South Africa.
FEMS Microbiol Lett. 1999 Jul 15;176(2):269-77. doi: 10.1111/j.1574-6968.1999.tb13672.x.
Genes encoding toxin-antitoxin proteins are frequently found on plasmids where they serve to stabilize the plasmid within a bacterial population. The toxin-antitoxin proteins do not increase the likelihood of a progeny cell receiving a plasmid but rather function as post-segregational killing mechanisms which decrease the proportion of cells that survive after losing the plasmid. These toxin-antitoxin couples therefore act as plasmid addiction systems. Several new proteic toxin-antitoxin systems have been identified and these systems appear to be ubiquitous on the chromosomes of bacteria and archaea. When placed on plasmids, these chromosomal systems also have the ability to stabilize plasmids and in at least one case, chromosomal- and plasmid-based toxin-antitoxin systems have been shown to interact. Recent findings regarding toxin-antitoxin systems and questions that have arisen as a result of these findings are reviewed.
编码毒素-抗毒素蛋白的基因经常出现在质粒上，它们在细菌群体中起到稳定质粒的作用。毒素-抗毒素蛋白不会增加子代细胞获得质粒的可能性，而是作为一种后分离杀伤机制，降低丢失质粒后存活细胞的比例。因此，这些毒素-抗毒素对充当了质粒成瘾系统。已经鉴定出几种新的蛋白质毒素-抗毒素系统，这些系统似乎在细菌和古细菌的染色体上普遍存在。当置于质粒上时，这些染色体系统也具有稳定质粒的能力，并且在至少一种情况下，已证明基于染色体和基于质粒的毒素-抗毒素系统会相互作用。本文综述了关于毒素-抗毒素系统的最新发现以及这些发现所引发的问题。
