Kinetic principles of ParA2-ATP cycling guide dynamic subcellular localizations in Vibrio cholerae.
Kinetic principles of ParA2-ATP cycling guide dynamic subcellular localizations in Vibrio cholerae.
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DOI：
10.1093/nar/gkad321
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发表时间：
2023-06-23
影响因子：
14.9
通讯作者：
Hwang LC
中科院分区：
文献类型：
--
作者：
Chodha SS;Brooks AC;Davis PJ;Ramachandran R;Chattoraj DK;Hwang LC
动态蛋白质梯度被用于复制染色体的空间组织和分离。然而，蛋白质梯度形成的机制以及如何在空间上组织染色体仍然知之甚少。在这里，我们已经确定了ParA2 ATPase亚细胞定位的动力学原理，ParA2 ATPase是多染色体细菌霍乱弧菌2号染色体分离的重要空间调节因子。我们发现，在霍乱弧菌细胞中，ParA2梯度自组织成动态的极间振荡。我们研究了ParA2的ATPase循环以及ParA2与ParB2和DNA的相互作用。在体外，ParA2-ATP二聚体在DNA的催化下发生限速构象转换，以获得DNA结合能力。这种活性的ParA2状态以更高阶低聚物的形式协同加载到DNA上。我们的结果表明，ParB2-parS2复合体的中细胞定位刺激了ATP水解和ParA2从类核中释放，产生了一个不对称的ParA2梯度，最大浓度朝向两极。这种快速解离加上缓慢的核苷酸交换和构象切换提供了一个时间滞后，允许ParA2重新分配到相反的极进行类核重新连接。基于我们的数据，我们提出了一个“拔河”模型，该模型利用ParA2的动态振荡来在空间上调节细菌染色体的对称分离和定位。ParA2梯度从一个极到另一个极振荡，通过拔河模型对称分离霍乱弧菌2号染色体姊妹基因座。
Dynamic protein gradients are exploited for the spatial organization and segregation of replicated chromosomes. However, mechanisms of protein gradient formation and how that spatially organizes chromosomes remain poorly understood. Here, we have determined the kinetic principles of subcellular localizations of ParA2 ATPase, an essential spatial regulator of chromosome 2 segregation in the multichromosome bacterium, Vibrio cholerae. We found that ParA2 gradients self-organize in V. cholerae cells into dynamic pole-to-pole oscillations. We examined the ParA2 ATPase cycle and ParA2 interactions with ParB2 and DNA. In vitro, ParA2-ATP dimers undergo a rate-limiting conformational switch, catalysed by DNA to achieve DNA-binding competence. This active ParA2 state loads onto DNA cooperatively as higher order oligomers. Our results indicate that the midcell localization of ParB2-parS2 complexes stimulate ATP hydrolysis and ParA2 release from the nucleoid, generating an asymmetric ParA2 gradient with maximal concentration toward the poles. This rapid dissociation coupled with slow nucleotide exchange and conformational switch provides for a temporal lag that allows the redistribution of ParA2 to the opposite pole for nucleoid reattachment. Based on our data, we propose a ‘Tug-of-war’ model that uses dynamic oscillations of ParA2 to spatially regulate symmetric segregation and positioning of bacterial chromosomes. ParA2 gradient oscillates from pole-to-pole to symmetrically segregate the sister loci of Vibrio cholerae Chromosome 2 via Tug-of-war model.
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影响因子：
6.4
作者：
Baek JH;Rajagopala SV;Chattoraj DK
通讯作者：
Chattoraj DK
影响因子：
4.5
作者：
Baek JH;Chattoraj DK
通讯作者：
Chattoraj DK
影响因子：
4.5
作者：
David A;Demarre G;Muresan L;Paly E;Barre FX;Possoz C
通讯作者：
Possoz C
影响因子：
11.4
作者：
Dunham, Thomas D.;Xu, Weijun;Schumacher, Maria A.
通讯作者：
Schumacher, Maria A.
DOI：
10.1073/pnas.0913060107
发表时间：
2010-03-09
影响因子：
11.1
作者：
Hui, Monica P.;Galkin, Vitold E.;Egelman, Edward H.
通讯作者：
Egelman, Edward H.