Collick A, Dunn M G, Jeffreys A J
Department of Genetics, University of Leicester, UK.
Nucleic Acids Res. 1991 Dec 11;19(23):6399-404. doi: 10.1093/nar/19.23.6399.
Msbp-1 is a minisatellite-specific DNA-binding protein. Using synthetic binding substrates, we now show that Msbp-1 binds not to double-stranded DNA, but exclusively to single-stranded DNA. Binding is specific to the guanine-rich strand of the minisatellite duplex, interactions with the cytosine-rich strand being undetectable by southwestern analysis. Furthermore, the binding site required for successful DNA-protein interactions appears to be two or more minisatellite repeat units. We have also isolated, by whole-genome PCR and cloning, one Msbp-1 binding site from the human genome. Again, the binding strand of this molecule contains a repetitive G-rich structure equivalent to that of a small minisatellite. These observations are discussed with respect to other single-stranded DNA-binding proteins known to play a role in recombination processes.
Msbp-1是一种小卫星特异性DNA结合蛋白。通过使用合成结合底物，我们现在表明Msbp-1不与双链DNA结合，而是仅与单链DNA结合。结合对小卫星双链体中富含鸟嘌呤的链具有特异性，通过蛋白质印迹分析未检测到与富含胞嘧啶的链的相互作用。此外，成功的DNA-蛋白质相互作用所需的结合位点似乎是两个或更多个小卫星重复单元。我们还通过全基因组PCR和克隆从人类基因组中分离出一个Msbp-1结合位点。同样，该分子的结合链包含与小卫星类似的富含G的重复结构。结合已知在重组过程中起作用的其他单链DNA结合蛋白对这些观察结果进行了讨论。
