A mammalian high mobility group protein recognizes any stretch of six A.T base pairs in duplex DNA.
A mammalian high mobility group protein recognizes any stretch of six A.T base pairs in duplex DNA.
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DOI：
10.1073/pnas.83.5.1276
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发表时间：
1986-03
影响因子：
11.1
通讯作者：
M. Solomon;F. Strauss;A. Varshavsky
中科院分区：
文献类型：
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作者：
M. Solomon;F. Strauss;A. Varshavsky
α-蛋白是一种高迁移率族蛋白，最初从非洲绿色猴细胞中纯化，基于其对猴α-卫星DNA的172-碱基对重复序列的亲和力。我们已经使用DNase I足迹法鉴定了猿猴病毒40 DNA上的50个α蛋白结合位点，从而确定了这种哺乳动物核蛋白的DNA结合特异性。α-蛋白以近似相等的亲和力结合双链体DNA中六个或更多个A × T碱基对的任何序列，结合五个A × T碱基对的许多（如果不是全部）序列，以及结合在其它（A + T）富集区域内的少量其它序列。与已充分表征的序列特异性DNA结合蛋白（如细菌阻遏物）不同，α蛋白在B-DNA的小沟内进行广泛接触。这些和相关的研究结果表明，而不是结合到一些特定的DNA序列，α-蛋白质识别的小沟的配置特征的短运行的A × T碱基对。我们讨论了α-蛋白的可能功能和α-蛋白与抗生素netropsin在DNA识别方面的相似性。
alpha-Protein is a high mobility group protein originally purified from African green monkey cells based on its affinity for the 172-base-pair repeat of monkey alpha-satellite DNA. We have used DNase I footprinting to identify 50 alpha-protein binding sites on simian virus 40 DNA and thereby to determine the DNA binding specificity of this mammalian nuclear protein. alpha-Protein binds with approximately equal affinity to any run of six or more A X T base pairs in duplex DNA, to many, if not all, runs of five A X T base pairs, and to a small number of other sequences within otherwise (A + T)-rich regions. Unlike well characterized sequence-specific DNA binding proteins such as bacterial repressors, alpha-protein makes extensive contacts within the minor groove of B-DNA. These and related findings indicate that, rather than binding to a few specific DNA sequences, alpha-protein recognizes a configuration of the minor groove characteristic of short runs of A X T base pairs. We discuss possible functions of alpha-protein and the similarities in DNA recognition by alpha-protein and the antibiotic netropsin.