The partition system of multidrug resistance plasmid TP228 includes a novel protein that epitomizes an evolutionarily distinct subgroup of the ParA superfamily
The partition system of multidrug resistance plasmid TP228 includes a novel protein that epitomizes an evolutionarily distinct subgroup of the ParA superfamily
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DOI：
10.1046/j.1365-2958.2000.02030.x
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发表时间：
2000-08-01
影响因子：
3.6
通讯作者：
Hayes, F
中科院分区：
文献类型：
--
作者：
Hayes, F
细菌、低拷贝数质粒的分离稳定性主要通过主动分配来促进。原型pi质粒分配系统的质粒特异性组分由两种蛋白质组成，帕拉（44.3 kDa）和pars（38.5 kDa），其与整合宿主因子结合，在质粒分配位点parS形成核蛋白复合物。该复合物是细胞分裂前质粒定向时空胞内运动的可能底物。多药耐药质粒TP 228的分区盒的遗传组织与pi范例的明显不同。TP 228系统包括ATP酶的帕拉超家族的新成员（ParF; 22.0 kDa），其中pi帕拉蛋白是原型。然而，ParF蛋白及其直系亲属形成了帕拉超家族的一个离散亚群，其在进化上与细胞分裂蛋白的MinD亚群的相关性大于与P1的帕拉的相关性。TP 228和P1分区模块的进一步不同之处在于前者不包括parS同源物，但确实指定了一种与P228无关的蛋白质（ParG; 8.6 kDa）。parF基因的同源物在真细菌基因组上广泛传播，表明ParF介导的分区可能是实现质粒分离稳定性的常见机制。
The segregational stability of bacterial, low-copy-number plasmids is promoted primarily by active partition, The plasmid-specified components of the prototypical pi plasmid partition system consist of two proteins, ParA (44.3 kDa) and pars (38.5 kDa), which, in conjunction with integration host factor, form a nucleoprotein complex at the plasmid partition site, parS. This complex is the probable substrate for the directed temporal and spatial intracellular movement of plasmids before cell division. The genetic organization of the partition cassette of the multidrug resistance plasmid TP228 differs markedly from that of the pi paradigm. The TP228 system includes a novel member (ParF; 22.0 kDa) of the ParA superfamily of ATPases, of which the pi ParA protein is the archetype. However, the ParF protein and its immediate relatives form a discrete subgroup of the ParA superfamily, which evolutionarily is more related to the MinD subgroup of cell division proteins than to ParA of P1. The TP228 and P1 partition modules differ further in that the former does not include a parS homologue, but does specify a protein (ParG; 8.6 kDa) unrelated to pare. Homologues of the parF gene are widely disseminated on eubacterial genomes, suggesting that ParF-mediated partition may be a common mechanism by which plasmid segregational stability is achieved.