Hda, a novel DnaA-related protein, regulates the replication cycle in Escherichia coli
Hda, a novel DnaA-related protein, regulates the replication cycle in Escherichia coli
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DOI：
10.1093/emboj/20.15.4253
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发表时间：
2001-08-01
期刊：
影响因子：
11.4
通讯作者：
Katayama, T
中科院分区：
文献类型：
--
作者：
Kato, J;Katayama, T
细菌 DnaA 蛋白与染色体复制起点结合，触发一系列起始反应，从而导致 DNA 聚合酶 III 的加载。在大肠杆菌中，一旦该聚合酶启动 DNA 合成，与 DnaA 结合的 ATP 就会被有效水解，产生 ADP 结合的失活形式。 DnaA 的这种负调节是通过与聚合酶的 β 亚基滑动钳结构相互作用而发生的，在重新启动的时间阻断中发挥作用。在这里，我们证明来自大肠杆菌的新型 DnaA 相关蛋白 Hda 对于体外和体内 DnaA 的调节失活至关重要。我们的结果表明，hda 基因是防止染色体复制过度启动和细胞活力所必需的。 Hda 属于类伴侣 ATP 酶家族 AAA(+)，DnaA 和某些启动 DNA 复制所必需的真核蛋白也是如此。我们提出，每个细胞周期一次的复制规则取决于 AAA(+) 蛋白的及时相互作用，这些蛋白构成了调节复制起始子活性的装置。
The bacterial DnaA protein binds to the chromosomal origin of replication to trigger a series of initiation reactions, which leads to the loading of DNA polymerase III. In Escherichia coli, once this polymerase initiates DNA synthesis, ATP bound to DnaA is efficiently hydrolyzed to yield the ADP-bound inactivated form. This negative regulation of DnaA, which occurs through interaction with the beta -subunit sliding clamp configuration of the polymerase, functions in the temporal blocking of re-initiation. Here we show that the novel DnaA-related protein, Hda, from E.coli is essential for this regulatory inactivation of DnaA in vitro and in vivo. Our results indicate that the hda gene is required to prevent over-initiation of chromosomal replication and for cell viability. Hda belongs to the chaperone-like ATPase family, AAA(+), as do DnaA and certain eukaryotic proteins essential for the initiation of DNA replication. We propose that the once-per-cell-cycle rule of replication depends on the timely interaction of AAA(+) proteins that comprise the apparatus regulating the activity of the initiator of replication.