Protein-directed DNA structure. I. Raman spectroscopy of a high-mobility-group box with application to human sex reversal
Protein-directed DNA structure. I. Raman spectroscopy of a high-mobility-group box with application to human sex reversal
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DOI：
10.1021/bi9900525
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发表时间：
2000-01-25
期刊：
影响因子：
2.9
通讯作者：
Thomas, GJ
中科院分区：
文献类型：
--
作者：
Benevides, JM;Chan, G;Thomas, GJ
蛋白质导向的DNA重组是转录、复制和重组机制的基础。序列特异性高迁移群（HMG）盒提供了基因表达调控中DNA重组的分子模型。含有DNA的HMG-box复合物的结构特征是小凹槽的扩张，向大凹槽的急剧弯曲，以及双螺旋的局部解绕。这种DNA重组的拉曼振动特征已经在对SRY HMG盒子的研究中被确定，该盒子由人类Y染色体的男性决定区域编码。我们观察到，在人类SRY-HMG:DNA复合体中，与DNA主干的振动模式相关的拉曼带受到了非常大的扰动，并且由于碱基解叠导致拉曼带强度大幅增加。相比之下，DNA主槽结合，如bZIP蛋白GCN4所发生的[j]。， Srinivasan， A. R, Olson， W. K, Weiss， M. A, and Thomas， G. J., Jr.（2000）生物化学39,548-556)，干扰DNA的拉曼特征只是轻微的。人类SRY-HMG:DNA复合体中小凹槽识别的拉曼标记主要是由于脱氧核糖部分的特定振动模式的扰动，可能反映了蛋白质和DNA非极性界面的脱溶。这些拉曼标记可以诊断蛋白质诱导的DNA弯曲，并被提议作为SRY中导致人类性别逆转的突变比较分析的基线。
Protein-directed reorganization of DNA underlies mechanisms of transcription, replication, and recombination. A molecular model for DNA reorganization in the regulation of gene expression is provided by the sequence-specific high-mobility-group (HMG) box. Structures of HMG-box complexes with DNA are characterized by expansion of the minor groove, sharp bending toward the major groove, and local unwinding of the double helix. The Raman vibrational signature of such DNA reorganization has been identified in a study of the SRY HMG box, encoded by the human male-determining region of the Y chromosome. We observe in the human SRY-HMG:DNA complex extraordinarily large perturbations to Raman bands associated with vibrational modes of the DNA backbone and accompanying large increases in intensities of Raman bands attributable to base unstacking. In contrast, DNA major-groove binding, as occurs for the bZIP protein GCN4 [Benevides, J. M., Li, T., Lu, X.-J., Srinivasan, A. R., Olson, W. K., Weiss, M. A., and Thomas, G. J., Jr. (2000) Biochemistry 39, 548-556], perturbs the Raman signature of DNA only marginally. Raman markers of minor-groove recognition in the human SRY-HMG:DNA complex are due primarily to perturbation of specific vibrational modes of deoxyribose moieties and presumably reflect desolvation at the nonpolar interface of protein and DNA. These Raman markers may be diagnostic of protein-induced DNA bending and:are proposed as a baseline for comparative analysis of mutations in SRY that cause human sex reversal.