染色质非组蛋白与DNA的特异性相互作用。

Specific interaction of chromatin non-histone proteins with DNA.

作者信息

Umansky S R, Kovalev Y I, Tokarskaya V I

出版信息

Biochim Biophys Acta. 1975 Mar 21;383(3):242-54. doi: 10.1016/0005-2787(75)90053-2.

Abstract

The interaction of different preparations of chromatin non-histone proteins of rat liver and thymus with homologous and heterologous DNA was studied. It is shown by the method of fixation of non-histone proteins-DNA complexes on nitrocellulose filters that: (1) all the non-histone proteins preparations studied form complexes with DNA in 0.02 M Tris--HCl (pH 7.5)--3 mM MgCl2; (2) the main part of non-histone proteins interacting with DNA binds to it non-specifically; (3) a small part of non-histone proteins interacts specifically with the homologous native DNA in 5 M urea; (4) both homologous and heterologous denatured DNA binds non-histone proteins more effectively than the native one; (5) the specific interaction of non-histone proteins with the homologous denatured DNA is observed both without urea and in its presence. The specific interaction of a small part of non-histone proteins with the homologous native and denatured DNA is also shown by the method of non-histone proteins chromatography on polyacrylamide--agarose columns containing DNA. The data obtained are discussed in the light of the possible non-histone proteins role in the specific regulation of the transcription process.

摘要

研究了大鼠肝脏和胸腺染色质非组蛋白不同制剂与同源及异源DNA的相互作用。通过将非组蛋白 - DNA复合物固定在硝酸纤维素滤膜上的方法表明：（1）所有研究的非组蛋白制剂在0.02 M Tris - HCl（pH 7.5） - 3 mM MgCl2中都能与DNA形成复合物；（2）与DNA相互作用的非组蛋白的主要部分非特异性地结合到DNA上；（3）一小部分非组蛋白在5 M尿素中与同源天然DNA特异性相互作用；（4）同源和异源变性DNA比天然DNA更有效地结合非组蛋白；（5）在没有尿素和有尿素存在的情况下，都观察到非组蛋白与同源变性DNA的特异性相互作用。通过在含有DNA的聚丙烯酰胺 - 琼脂糖柱上对非组蛋白进行色谱分析的方法，也表明了一小部分非组蛋白与同源天然和变性DNA的特异性相互作用。根据非组蛋白在转录过程特异性调节中可能发挥的作用，对所获得的数据进行了讨论。