Refined 1.8 A crystal structure of the lambda repressor-operator complex.
Refined 1.8 A crystal structure of the lambda repressor-operator complex.
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DOI：
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发表时间：
1992
影响因子：
5.6
通讯作者：
L. Beamer;C. Pabo
中科院分区：
文献类型：
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作者：
L. Beamer;C. Pabo
抑制-算子配合物的晶体结构在1.8 A分辨率下被细化到18.9%的r因子。利用低温下收集的数据，这种改进揭示了n端臂的结构，并表明阻遏子与伪对称算子位点的两半的相互作用显着不同。复合物的两个半部分在靠近操作位点的外缘处最为相似（在lambda和434阻遏子进行相似接触的区域），但它们在靠近操作位点的中心处变得越来越不同。在这个位点的中心附近有显著的差异，在那里，手臂似乎只与一半的DNA位点有重要的接触。这为噬菌体lambda中算子位点的对齐提供了一种新的方法。高分辨率结构证实了许多先前注意到的复合物的特征，但也揭示了一些新的蛋白质- dna接触。它还提供了一个更好的视图，结合接触的不同残基和蛋白质的不同区域的广泛的氢键网络，并揭示了有关螺旋-转-螺旋（HTH）区域的重要新细节，以及许多水分子在配合物中的位置。
The crystal structure of the lambda repressor-operator complex has been refined to an R-factor of 18.9% at 1.8 A resolution. This refinement, using data collected at low temperature, has revealed the structure of the N-terminal arm and shows that the interactions of repressor with the two halves of the pseudo-symmetric operator site are significantly different. The two halves of the complex are most similar near the outer edge of the operator site (in a region where the lambda and 434 repressors make similar contacts), but they become increasingly different toward the center of the operator. There are striking differences near the center of the site where it appears that the arm makes significant contacts to only one half of the DNA site. This suggested a new way of aligning the operator sites in phage lambda. The high resolution structure confirms many of the previously noted features of the complex, but also reveals a number of new protein-DNA contacts. It also gives a better view of the extensive H-bonding networks that couple contacts made by different residues and different regions of the protein, and reveals important new details about the helix-turn-helix (HTH) region, and the positions of many water molecules in the complex.