Escherichia coli transcription termination factor Rho binds and hydrolyzes ATP using a single class of three sites.
Escherichia coli transcription termination factor Rho binds and hydrolyzes ATP using a single class of three sites.
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大肠杆菌转录终止因子 Rho 使用单一类别的三个位点结合并水解 ATP。
DOI：
10.1021/bi002253a
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发表时间：
2001
期刊：
影响因子：
2.9
通讯作者：
Stitt,BL
中科院分区：
文献类型：
--
作者：
Stitt,BL
大肠杆菌转录终止因子Rho利用三磷酸腺苷水解酶的能量沿核糖核酸传递5‘→3’。我们之前的研究表明，六聚体Rho蛋白在活性部位与三个ATP分子结合，并且三个结合的ATP分子在RNA结合时的水解是顺序的。关于Rho上额外的ATP结合位点的报道，也出现了Rho ATP水解活性的其他模型。在这里，我们提供了来自结合、同位素分配和快速混合/化学猝灭实验的进一步证据，支持在Rho上只存在三个等同的ATP结合位点，这三个结合位点是催化位点，并依次开火。这些结果被合并到提出的沿RNA定向Rho跟踪的机制中。
Escherichia colitranscription termination factor Rho uses the energy of ATP hydrolysis to travel 5‘ → 3‘ along RNA. We previously showed that the hexameric Rho protein binds three molecules of ATP in active sites and that hydrolysis of the three bound ATP molecules upon RNA binding is sequential. Other models of Rho ATP hydrolysis activity have arisen from reports of additional ATP binding sites on Rho. Here we present further evidence from binding, isotope partitioning, and rapid mix/chemical quench experiments, in support of the presence of only three equivalent ATP binding sites on Rho that are catalytic sites and that fire sequentially. These results are incorporated into a proposed mechanism for directional Rho tracking along RNA.