McPherson A, Jurnak F, Wang A, Molineux I, Rich A
J Supramol Struct. 1979;10(4):457-65. doi: 10.1002/jss.400100408.
The structure of the gene 5 DNA unwinding protein from bacteriophage fd has been solved to 2.3-A resolution by X-ray diffraction techniques. The molecule contains an extensive cleft region that we have identified as the DNA binding site on the basis of the residues that comprise its surface. The interior of the groove has a rather large number of basic amino acid residues that serve to draw the polynucleotide backbone into the cleft. Arrayed along the external edges of the groove are a number of aromatic amino acid side groups that are in position to stack upon the bases of the DNA and fix it in place. The structure and binding mechanism as we visualize it appear to be fully consistent with evidence provided by physical-chemical studies of the protein in solution.
通过X射线衍射技术，噬菌体fd基因5解旋蛋白的结构已解析至2.3埃分辨率。该分子包含一个广泛的裂隙区域，基于构成其表面的残基，我们已将其确定为DNA结合位点。凹槽内部有相当多的碱性氨基酸残基，用于将多核苷酸主链拉入裂隙。沿着凹槽的外部边缘排列着一些芳香族氨基酸侧基，它们能够堆叠在DNA的碱基上并将其固定在位。我们所设想的结构和结合机制似乎与该蛋白质在溶液中的物理化学研究提供的证据完全一致。
