Interactions of RadB, a DNA repair protein in archaea, with DNA and ATP
Interactions of RadB, a DNA repair protein in archaea, with DNA and ATP
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DOI：
10.1016/j.jmb.2006.02.010
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发表时间：
2006-04-21
影响因子：
5.6
通讯作者：
Bolt, EL
中科院分区：
文献类型：
--
作者：
Guy, CP;Haldenby, S;Bolt, EL
RecA重组酶家族(RecA, Rad51；RadA和UvsX)利用保守的DNA结合模块和共同的核心atp酶结构域催化同源DNA分子之间的链交换。在古细菌中鉴定出RadB。基于保守的atp酶序列，它被认为是rad51样蛋白。然而，RadB不能催化链交换，也不能有效地转化ATP。RadB确实与DNA结合，我们报道了在RadB末端高度保守的三联体残基（Lys-His-Arg），对DNA结合至关重要。这与在kodakaraensis热球菌RadB的原子结构中发现的形成高度保守残基的“基本斑块”的基序是一致的。由于三联体基序在哺乳动物Rad51-paralogues的XRCC2的C端也是保守的，我们提出了一个系统发育分析，澄清了RadB， Rad51-paralogues和重组酶之间的关系。我们利用遗传学和生物化学研究RadB和ATP之间的相互作用；RadB与ATP结合是促进火山盐铁在紫外线照射后存活的必要条件，ATP诱导RadB发生明显构象变化，而非其他ntp。这是对radB的首次遗传分析，并确立了它对维持古细菌基因组稳定性的重要性。ATP诱导的RadB构象变化可以解释先前的报道，即RadB根据ATP的存在或不存在来控制Hjc对Holliday结的分解。(c) 2006 Elsevier Ltd.版权所有。
The RecA family of recombinases (RecA, Rad51., RadA and UvsX) catalyse strand-exchange between homologous DNA molecules by utilising conserved DNA-binding modules and a common core ATPase domain. RadB was identified in archaea. as a Rad51-like protein on the basis of conserved ATPase sequences. However, RadB does not catalyse strand exchange and does not turn over ATP efficiently. RadB does bind DNA, and we report a triplet of residues (Lys-His-Arg) that is highly conserved at the RadB terminus, and is crucial for DNA binding. This is consistent with the motif forming a "basic patch" of highly conserved residues identified in an atomic structure of RadB from Thermococcus kodakaraensis. As the triplet motif is conserved at the C terminus of XRCC2 also, a mammalian Rad51-paralogue, we present a phylogenetic analysis that clarifies the relationship between RadB, Rad51-paralogues and recombinases. We investigate interactions between RadB and ATP using genetics and biochemistry; ATP binding by RadB is needed to promote survival of Haloferax volcanii after UV irradiation, and ATP, but not other NTPs, induces pronounced conformational change in RadB. This is the first genetic analysis of radB, and establishes its importance for maintaining genome stability in archaea. ATP-induced conformational change in RadB may explain previous reports that RadB controls Holliday junction resolution by Hjc, depending on the presence or the absence of ATP. (c) 2006 Elsevier Ltd. All rights reserved.