School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia.
School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia.
Plasmid. 2022 Sep-Nov;123-124:102654. doi: 10.1016/j.plasmid.2022.102654. Epub 2022 Nov 11.
Though IncC and IncA plasmids are compatible, they exert high level exclusion on one another. Here, the question of whether the presence of an SGI1 family element in the donor can overcome the exclusion of an IncC plasmid exerted by an IncC or IncA plasmid in the recipient was investigated. The transfer of the integrative mobilizable element SGI1 and its many variant forms into a new host is dependent on transfer machinery supplied by IncC or IncA plasmids. SGI1 elements include the determinants of a mobilization system and three genes that encode homologues of transfer proteins including TraG. Exclusion of a complete IncC plasmid by a complete IncA or IncC plasmid in the recipient was not ameliorated by an SGI1 element in the donor. However, transfer of the SGI was unaffected indicating that a functional mating apparatus was formed. The presence of only the plasmid-derived eexC or eexA gene in the recipient exerted high level exclusion on an incoming IncC plasmid and this was overcome by an SGI1 variant in the donor. Hence, the SGI affects only entry exclusion and additional plasmid features must influence other routes to plasmid exclusion.
虽然 IncC 和 IncA 质粒是兼容的，但它们对彼此施加了高水平的排斥。在这里，研究了供体中是否存在 SGI1 家族元件是否可以克服受体中 IncC 或 IncA 质粒对 IncC 质粒的排斥。整合可移动元件 SGI1 及其许多变体形式的转移到新宿主取决于 IncC 或 IncA 质粒提供的转移机制。SGI1 元件包括一个动员系统的决定因素和三个编码转移蛋白同源物的基因，包括 TraG。供体中的 SGI1 元件不能改善受体中完整 IncA 或 IncC 质粒对完整 IncC 质粒的排斥。然而，SGI 的转移不受影响，表明形成了功能交配装置。在受体中仅存在质粒衍生的 eexC 或 eexA 基因对传入的 IncC 质粒施加高水平排斥，这被供体中的 SGI1 变体克服。因此，SGI 仅影响进入排斥，并且其他质粒特征必须影响其他排斥质粒的途径。
