Escherichia coli PriA protein, two modes of DNA binding and activation of ATP hydrolysis
Escherichia coli PriA protein, two modes of DNA binding and activation of ATP hydrolysis
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DOI：
10.1074/jbc.m701848200
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发表时间：
2007-07-06
影响因子：
4.8
通讯作者：
Masai, Hisao
中科院分区：
文献类型：
--
作者：
Tanaka, Taku;Mizukoshi, Toshimi;Masai, Hisao
大肠杆菌PriA蛋白在抑制复制叉的加工过程中起重要作用。PriA作为一个传感器/稳定剂的一个被捕的复制叉，并最终促进重新启动的DNA复制通过装配的一个primosome。PriA携带3'末端结合口袋，其高亲和力结合特异性被捕叉以及其生物学功能所需。我们在这里表明，PriA结合DNA的方式依赖于或独立于3'末端识别。前一种结合模式需要存在于181-残基DNA结合结构域的N-末端一半处的3'末端结合口袋，并且在模板DNA上表现出特异性二分相互作用。后一种模式与口袋功能无关，但需要相同结构域的C-末端一半。PriA的ATP水解活性可以通过两种结合模式中的任一种在体外被刺激。我们提出了结构的PriA绑定到各种被捕的复制叉结构，并讨论其在解旋酶激活和ATP水解的影响。
Escherichia coli PriA protein plays crucial roles in processing of arrested replication forks. PriA serves as a sensor/stabilizer for an arrested replication fork and eventually promotes restart of DNA replication through assembly of a primosome. PriA carries a 3' terminus binding pocket required for its high affinity binding to a specific arrested fork as well as for its biological functions. We show here that PriA binds to DNA in a manner either dependent on or independent of 3' terminus recognition. The former mode of binding requires the 3' terminus binding pocket present at the N- terminal half of the 181-residue DNA binding domain and exhibits specific bipartite interaction on the template DNA. The latter mode is independent of the pocket function, but requires the C-terminal half of the same domain. ATP hydrolysis activity of PriA can be stimulated in vitro by either of the two binding modes. We propose architecture of PriA bound to various arrested replication fork structures and discuss its implication in helicase activation and ATP hydrolysis.