ParB-stimulated nucleotide exchange regulates a switch in functionally distinct ParA activities
ParB-stimulated nucleotide exchange regulates a switch in functionally distinct ParA activities
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DOI：
10.1016/s1097-2765(02)00594-4
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发表时间：
2002-08-01
期刊：
影响因子：
16
通讯作者：
Gober, JW
中科院分区：
文献类型：
--
作者：
Easter, J;Gober, JW
新月柄杆菌的帕拉和ParB属于涉及染色体分离的细菌蛋白的保守家族。ParB与复制起点附近的DNA序列结合，并在DNA复制开始后不久定位于相对的细胞两极。帕拉与保守且广泛分布的ATP酶家族具有同源性。在这里，我们表明，ParB调节的帕拉ATP酶活性，促进核苷酸交换的方式让人想起真核G蛋白的交换因子。此外，我们证明，ADP结合的帕拉结合单链DNA，而ATP结合的形式解离ParB从其DNA结合位点。增加ParA-ADP在细胞中的分数抑制细胞分裂，表明这种简单的核苷酸开关可能调节胞质分裂。
ParA and ParB of Caulobacter crescentus belong to a conserved family of bacterial proteins implicated in chromosome segregation. ParB binds to DNA sequences adjacent to the origin of replication and localizes to opposite cell poles shortly following the initiation of DNA replication. ParA has homology to a conserved and widespread family of ATPases. Here, we show that ParB regulates the ParA ATPase activity by promoting nucleotide exchange in a fashion reminiscent of the exchange factors of eukaryotic G proteins. Furthermore, we demonstrate that ADP-bound ParA binds single-stranded DNA, whereas the ATP-bound form dissociates ParB from its DNA binding sites. Increasing the fraction of ParA-ADP in the cell inhibits cell division, suggesting that this simple nucleotide switch may regulate cytokinesis.