Bacterial DNA segregation dynamics mediated by the polymerizing protein ParF
Bacterial DNA segregation dynamics mediated by the polymerizing protein ParF
复制标题
DOI：
10.1038/sj.emboj.7600619
复制
发表时间：
2005-04-06
期刊：
影响因子：
11.4
通讯作者：
Hayes, F
中科院分区：
文献类型：
--
作者：
Barillá, D;Rosenberg, MF;Hayes, F
原核 DNA 分离最常见的是 Walker 型 ParA 超家族的成员。在这里，我们展示了 TP228 质粒指定的 ParF 分区蛋白是一种 ParA ATP 酶，可在体外组装成广泛的丝状结构。聚合通过 ATP 结合而增强，并且不需要核苷酸水解。对 Walker A 基序保守残基突变的分析建立了丝动力学和 DNA 分配之间的功能耦合。伴侣分配蛋白 ParG 在 ParF 聚合过程中发挥两个独立的作用。 ParF 与肌动蛋白或微管蛋白家族的原核聚合蛋白无关，但它是 MinD 细胞分裂蛋白的同源物，MinD 细胞分裂蛋白也组装成细丝。 ParF 和 MinD 聚合物的超微结构非常相似。这表明原核细胞中 DNA 分离和胞质分裂之间存在进化平行性，并揭示了普遍存在的 ParA 型蛋白介导的质粒和染色体分离的潜在分子机制。
Prokaryotic DNA segregation most commonly involves members of the Walker-type ParA superfamily. Here we show that the ParF partition protein specified by the TP228 plasmid is a ParA ATPase that assembles into extensive filaments in vitro. Polymerization is potentiated by ATP binding and does not require nucleotide hydrolysis. Analysis of mutations in conserved residues of the Walker A motif established a functional coupling between filament dynamics and DNA partitioning. The partner partition protein ParG plays two separable roles in the ParF polymerization process. ParF is unrelated to prokaryotic polymerizing proteins of the actin or tubulin families, but is a homologue of the MinD cell division protein, which also assembles into filaments. The ultrastructures of the ParF and MinD polymers are remarkably similar. This points to an evolutionary parallel between DNA segregation and cytokinesis in prokaryotic cells, and reveals a potential molecular mechanism for plasmid and chromosome segregation mediated by the ubiquitous ParA-type proteins.