Identification of four GyrA residues involved in the DNA breakage-reunion reaction of DNA gyrase
Identification of four GyrA residues involved in the DNA breakage-reunion reaction of DNA gyrase
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DOI：
10.1016/s0022-2836(02)00048-7
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发表时间：
2002-04-26
影响因子：
5.6
通讯作者：
Maxwell, A
中科院分区：
文献类型：
--
作者：
Hockings, SC;Maxwell, A
通过DNA促旋酶的DNA超螺旋包括DNA螺旋的切割，另一个螺旋通过断裂，以及第一个螺旋的重新连接。裂解-再连接反应涉及与促旋酶（A（2）B（2））复合物的GyrA亚基形成5-磷酸酪氨酸中间体。我们报告的特征附近的活性位点的酪氨酸残基GyrA预测影响的切割-再连接反应的促旋酶的突变。我们发现Arg 32，Arg 47，His 78和His 80的突变抑制了DNA超螺旋和促旋酶的其他反应。这些效应是由这些残基参与DNA切割反应引起的;再连接在很大程度上不受这些突变的影响。我们表明，这些残基与活性位点酪氨酸残基上的GyrA二聚体的相对亚基在裂解-再连接反应。(C)2002爱思唯尔科技有限公司版权所有。
DNA supercoiling by DNA gyrase involves the cleavage of a DNA helix, the passage of another helix through the break, and the religation of the first helix. The cleavage-religation reaction involves the formation of a 5-phosphotyrosine intermediate with the GyrA subunit of the gyrase (A(2)B(2)) complex. We report the characterization of mutations near the active-site tyrosine residue in GyrA predicted to affect the cleavage-religation reaction of gyrase. We find that mutations at Arg32, Arg47, His78 and His80 inhibit DNA supercoiling and other reactions of gyrase. These effects are caused by the involvement of these residues in the DNA cleavage reaction; religation is largely unaffected by these mutations. We show that these residues cooperate with the active-site tyrosine residue on the opposite subunit of the GyrA dimer during the cleavage-religation reaction. (C) 2002 Elsevier Science Ltd. All rights reserved.