Intermediates in homologous pairing promoted by recA protein. Isolation and characterization of active presynaptic complexes.
Intermediates in homologous pairing promoted by recA protein. Isolation and characterization of active presynaptic complexes.
复制标题
由recA蛋白促进的同源配对的中间体。
DOI：
10.1016/0022-2836(85)90405-x
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发表时间：
1985
影响因子：
5.6
通讯作者：
Chase,JW
中科院分区：
文献类型：
--
作者：
Tsang,SS;Muniyappa,K;Azhderian,E;Gonda,DK;Radding,CM;Flory,J;Chase,JW
recA蛋白通过蛋白质首先在单链DNA上聚合的有序反应促进同源配对和链交换。这种突触前的中间体，它可以在存在或不存在ofEscherichia coli单链结合蛋白（SSB）的情况下形成，已经通过凝胶过滤分离和表征。在饱和时，纯化的复合物含有一个分子的recA蛋白每3.6个核苷酸残基的单链DNA。在SSB存在下形成的复合物含有每15个核苷酸残基最多一个SSB分子，但分离复合物的不同制剂中SSB的含量似乎与recA蛋白的含量呈负相关。即使当它们失去了多达三分之一的recA蛋白时，突触前复合物仍然可以保持活性，因为稳定的关节分子的形成主要取决于recA蛋白与单链DNA在对应于双链体底物末端的局部区域中的结合。
recA protein promotes homologous pairing and strand exchange by an ordered reaction in which the protein first polymerizes on single-stranded DNA. This presynaptic intermediate, which can be formed either in the presence or absence ofEscherichia colisingle-stranded binding protein (SSB), has been isolated by gel filtration and characterized. At saturation, purified complexes contained one molecule of recA protein per 3.6 nucleotide residues of single-stranded DNA. Complexes that had been formed in the presence of SSB contained up to one molecule of SSB per 15 nucleotide residues, but the content of SSB in different preparations of isolated complexes appeared to be inversely related to the content of recA protein. Even when they have lost as much as a third of their recA protein, presynaptic complexes can retain activity, because the formation of stable joint molecules depends principally on the binding of recA protein to the single-stranded DNA in the localized region that corresponds to the end of the duplex substrate.