VISUALIZATION OF RECA PROTEIN AND ITS ASSOCIATION WITH DNA - A PRIMING EFFECT OF SINGLE-STRAND-BINDING PROTEIN
VISUALIZATION OF RECA PROTEIN AND ITS ASSOCIATION WITH DNA - A PRIMING EFFECT OF SINGLE-STRAND-BINDING PROTEIN
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DOI：
10.1016/0092-8674(82)90054-x
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发表时间：
1982-01-01
期刊：
影响因子：
64.5
通讯作者：
RADDING, CM
中科院分区：
文献类型：
--
作者：
FLORY, J;RADDING, CM
RecA蛋白与单链DNA的化学计量相互作用促进单链与双链DNA的同源配对和随后的异源双链接头的极性形成。大肠杆菌单链结合（SSB）蛋白增强这些反应。电子显微镜观察表明这些相互作用的结构基础。在没有三磷酸或DNA的情况下，RecA蛋白形成短的线性细丝。随着环状单链DNA的加入，它形成了延伸的环状细丝以及蛋白质和DNA的塌陷和聚集的复合物。延伸的环形丝在外观上是刚性和规则的，与SSB蛋白和单链DNA形成的卷曲结构形成对比。这两种蛋白质一起形成混合细丝，其大多类似于含有RecA蛋白的延伸结构;此外，SSB蛋白加速延伸细丝的形成超过50倍，以异质聚集体为代价增加这些结构的产量。其他观察结果进一步定义了RecA蛋白与部分单链DNA的相互作用，以及ATPyS对RecA蛋白形成聚合结构的趋势的影响，即使在没有DNA的情况下。
A stoichiometric interaction of RecA protein with single-stranded DNA promotes homologous pairing of the single strand with duplex DNA and subsequent polar formation of a heteroduplex joint. Escherichia coli single-strand-binding(SSB) protein augments these reactions. Electron microscopic observations suggest structural bases for these interactions. Without triphosphates or DNA, RecA protein forms short linear filaments. With added circular single-stranded DNA, it forms extended circular filaments as well as collapsed and aggregated complexes of protein and DNA. The extended circular filaments are stiff and regular in appearance, contrasting with the convoluted structure formed by SSB protein and single-stranded DNA. Together, these two proteins form mixed filaments, which mostly resemble the extended structures containing RecA protein; moreover, SSB protein accelerates formation of extended filaments more than 50-fold, increasing the yield of these structures at the expense of heterogeneous aggregates. Other observations further define the interactions of RecA protein with partially single-stranded DNA, and the effects of ATPyS on the tendency of RecA protein to form polymeric structures even in the absence of DNA.