Segrosome assembly at the pliable parH centromere.
Segrosome assembly at the pliable parH centromere.
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DOI：
10.1093/nar/gkr115
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发表时间：
2011-07
影响因子：
14.9
通讯作者：
Hayes F
中科院分区：
文献类型：
--
作者：
Wu M;Zampini M;Bussiek M;Hoischen C;Diekmann S;Hayes F
多抗性质粒TP228的segrosome包括ParF （ParA atp酶超家族成员）和ParG（带-螺旋-螺旋因子），它们共同组装在parH着丝粒上。在这里，我们证明了独特的parH位点（~ 100-bp）由一系列简并的四聚体盒组成，这些盒中散布着富含at的间隔物。虽然许多连续的at步骤暗示了固有的曲率，但parH缺乏固有的弯曲。连续删除parH四聚体逐渐降低着丝粒功能。然而，不同的亚位点可以重新排列成不同的几何形状，以适应着丝粒的活性，这表明该位点在体内具有高度弹性。ParG协同包裹parH：正确的着丝粒结合需要蛋白质的n端柔性尾巴，这调节了ParG的着丝粒结合亲和力。ParG带状-螺旋-螺旋结构域与四聚体盒中的主要凹槽碱基的相互作用可能提供了着丝粒的直接读出。相反，富含at的间隔可能与间接读出有关，间接读出介导组装在相邻盒子上的ParG二聚体之间的协同性。ParF单独不结合parH，而是与ParG相互作用加载到凝体中，从而微妙地改变着丝粒构象。将ParF装配到络合物中，需要ParG中的n端柔性尾与ParF接触。
The segrosome of multiresistance plasmid TP228 comprises ParF, which is a member of the ParA ATPase superfamily, and the ParG ribbon–helix–helix factor that assemble jointly on the parH centromere. Here we demonstrate that the distinctive parH site (∼100-bp) consists of an array of degenerate tetramer boxes interspersed by AT-rich spacers. Although numerous consecutive AT-steps are suggestive of inherent curvature, parH lacks an intrinsic bend. Sequential deletion of parH tetramers progressively reduced centromere function. Nevertheless, the variant subsites could be rearranged in different geometries that accommodated centromere activity effectively revealing that the site is highly elastic in vivo. ParG cooperatively coated parH: proper centromere binding necessitated the protein's N-terminal flexible tails which modulate the centromere binding affinity of ParG. Interaction of the ParG ribbon–helix–helix domain with major groove bases in the tetramer boxes likely provides direct readout of the centromere. In contrast, the AT-rich spacers may be implicated in indirect readout that mediates cooperativity between ParG dimers assembled on adjacent boxes. ParF alone does not bind parH but instead loads into the segrosome interactively with ParG, thereby subtly altering centromere conformation. Assembly of ParF into the complex requires the N-terminal flexible tails in ParG that are contacted by ParF.
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影响因子：
14.9
作者：
DIEKMANN, S
通讯作者：
DIEKMANN, S
影响因子：
3.6
作者：
Hayes, F
通讯作者：
Hayes, F
影响因子：
3.6
作者：
Grigoriev, PS;Lobocka, MB
通讯作者：
Lobocka, MB
影响因子：
3.5
作者：
De Mey M;Maertens J;Lequeux GJ;Soetaert WK;Vandamme EJ
通讯作者：
Vandamme EJ
影响因子：
3.6
作者：
Golovanov, AP;Barillà, D;Lian, LY
通讯作者：
Lian, LY