Probing the DNA sequence specificity of Escherichia coli RECA protein.
Probing the DNA sequence specificity of Escherichia coli RECA protein.
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DOI：
10.1093/nar/gkl302
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发表时间：
2006
影响因子：
14.9
通讯作者：
Bell CE
中科院分区：
文献类型：
--
作者：
Rajan R;Wisler JW;Bell CE
大肠杆菌RecA蛋白催化同源重组的中心DNA链交换步骤，这对于双链DNA断裂的修复是必不可少的。在该反应中，RecA首先在单链DNA（ssDNA）上聚合以形成右旋螺旋细丝，其中每3nt的ssDNA具有一个单体。RecA通常与ssDNA的任何序列结合，但偏好富含GT的序列，如重组热点Chi（5 ′-GCTGGTGG-3 ′）中所发现的。当该序列位于寡核苷酸内时，RecA的结合相对于它是分阶段的，具有三个核苷酸的周期性。这意味着在RecA单体内有三个独立的核苷酸结合位点，它们可能表现出对四种不同核苷酸的偏好。在这里，我们已经使用RecA辅助蛋白酶测定进一步探测大肠杆菌RecA蛋白的ssDNA序列特异性。测定了在RecA、ADP-AlF_4和64种不同的三核苷酸重复的15聚体寡核苷酸存在下λ阻遏物片段的自切割程度。RecA的辅助蛋白酶活性强烈依赖于ssDNA序列，其中TGG重复序列提供迄今为止最高的辅助蛋白酶活性，而富含GC和AT的序列最低。对于选定的三核苷酸重复序列，DNA依赖的ATP酶和DNA结合活性的RecA也被确定。RecA的DNA结合活性和辅助蛋白酶活性具有相同的序列依赖性，这与RecA的ATP酶活性基本相反。RecA的生物学机制方面的影响进行了讨论。
Escherichia coli RecA protein catalyzes the central DNA strand-exchange step of homologous recombination, which is essential for the repair of double-stranded DNA breaks. In this reaction, RecA first polymerizes on single-stranded DNA (ssDNA) to form a right-handed helical filament with one monomer per 3 nt of ssDNA. RecA generally binds to any sequence of ssDNA but has a preference for GT-rich sequences, as found in the recombination hot spot Chi (5′-GCTGGTGG-3′). When this sequence is located within an oligonucleotide, binding of RecA is phased relative to it, with a periodicity of three nucleotides. This implies that there are three separate nucleotide-binding sites within a RecA monomer that may exhibit preferences for the four different nucleotides. Here we have used a RecA coprotease assay to further probe the ssDNA sequence specificity of E.coli RecA protein. The extent of self-cleavage of a λ repressor fragment in the presence of RecA, ADP-AlF4 and 64 different trinucleotide-repeating 15mer oligonucleotides was determined. The coprotease activity of RecA is strongly dependent on the ssDNA sequence, with TGG-repeating sequences giving by far the highest coprotease activity, and GC and AT-rich sequences the lowest. For selected trinucleotide-repeating sequences, the DNA-dependent ATPase and DNA-binding activities of RecA were also determined. The DNA-binding and coprotease activities of RecA have the same sequence dependence, which is essentially opposite to that of the ATPase activity of RecA. The implications with regard to the biological mechanism of RecA are discussed.
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影响因子：
16.8
作者：
Conway, AB;Lynch, TW;Rice, PA
通讯作者：
Rice, PA
影响因子：
4.8
作者：
Bork, JM;Cox, MM;Inman, RB
通讯作者：
Inman, RB
DOI：
10.1073/pnas.151242898
发表时间：
2001-07-31
影响因子：
11.1
作者：
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通讯作者：
Libchaber, A
影响因子：
14.9
作者：
Biet, E;Sun, JS;Dutreix, M
通讯作者：
Dutreix, M
影响因子：
11.4
作者：
ROSSELLI, W;STASIAK, A
通讯作者：
STASIAK, A