RECOGNITION OF A DNA OPERATOR BY THE REPRESSOR OF PHAGE-434 - A VIEW AT HIGH-RESOLUTION
RECOGNITION OF A DNA OPERATOR BY THE REPRESSOR OF PHAGE-434 - A VIEW AT HIGH-RESOLUTION
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DOI：
10.1126/science.3187531
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发表时间：
1988-11-11
期刊：
影响因子：
56.9
通讯作者：
HARRISON, SC
中科院分区：
文献类型：
--
作者：
AGGARWAL, AK;RODGERS, DW;HARRISON, SC
温和噬菌体的阻遏物如434和λ通过结合一组DNA操纵基因位点来控制转录。阻遏物对每个位点的不同亲和力确保了有效的调节。高分辨率X射线晶体学被用来研究噬菌体434阻遏物与合成DNA操纵子复合物的DNA结合结构域。该结构显示通过与大沟中的碱基对直接相互作用识别操纵子，结合DNA在结合阻遏物上采用所需构象的序列依赖性能力。特别是，操纵子碱基对之间的三中心分叉氢键网络有助于解释为什么434阻遏物更喜欢某些位点。这些键稳定了结合的DNA的构象，只能与某些序列形成。
The repressors of temperate bacteriophages such as 434 and lambda control transcription by binding to a set of DNA operator sites. The different affinity of repressor for each of these sites ensures efficient regulation. High-resolution x-ray crystallography was used to study the DNA-binding domain of phage 434 repressor in complex with a synthetic DNA operator. The structure shows recognition of the operator by direct interactions with base pairs in the major groove, combined with the sequence-dependent ability of DNA to adopt the required conformation on binding repressor. In particular, a network of three-centered bifurcated hydrogen bonds among base pairs in the operator helps explain why 434 repressor prefers certain sites over others. These bonds, which stabilize the conformation of the bound DNA, can form only with certain sequences.