Huth J R, Bewley C A, Nissen M S, Evans J N, Reeves R, Gronenborn A M, Clore G M
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-520, USA.
Nat Struct Biol. 1997 Aug;4(8):657-65. doi: 10.1038/nsb0897-657.
The solution structure of a complex between a truncated form of HMG-I(Y), consisting of the second and third DNA binding domains (residues 51-90), and a DNA dodecamer containing the PRDII site of the interferon-beta promoter has been solved by multidimensional nuclear magnetic resonance spectroscopy. The stoichiometry of the complex is one molecule of HMG-I(Y) to two molecules of DNA. The structure reveals a new architectural minor groove binding motif which stabilizes B-DNA, thereby facilitating the binding of other transcription factors in the opposing major groove. The interactions involve a central Arg-Gly-Arg motif together with two other modules that participate in extensive hydrophobic and polar contracts. The absence of one of these modules in the third DNA binding domain accounts for its-100 fold reduced affinity relative to the second one.
由HMG-I(Y)的截短形式（由第二和第三DNA结合结构域组成，残基51 - 90）与包含干扰素-β启动子PRDII位点的DNA十二聚体形成的复合物的溶液结构已通过多维核磁共振光谱法解析。该复合物的化学计量比为一个HMG-I(Y)分子对应两个DNA分子。该结构揭示了一种新的结构型小沟结合基序，其可稳定B-DNA，从而促进其他转录因子在相对的大沟中的结合。相互作用涉及一个中心Arg-Gly-Arg基序以及另外两个参与广泛疏水和极性相互作用的模块。第三个DNA结合结构域中缺少这些模块之一，导致其相对于第二个结构域的亲和力降低了100倍。
