Reddy T R, Suryanarayana T
School Of Life Sciences, University of Hyderabad, India.
J Biol Chem. 1989 Oct 15;264(29):17298-308.
Four DNA binding histone-like proteins have been purified from the nucleoid of the acidothermophilic archaebacterium Sulfolobus acidocaldarius to homogeneity employing DNA-cellulose chromatography and carboxymethylcellulose chromatography. The molecular weights of these proteins are in the range 8,000-12,500. Immunoblotting results suggest that a few antigenic determinants are common among these proteins which could not be detected by immunodiffusion. Spectroscopic properties of the proteins have been studied. The amino acid compositions of these proteins show both similarities and differences with histones and prokaryotic histone-like proteins. All of the four proteins bind native and denatured DNAs and single stranded RNA with differing affinities. Three of the proteins, denoted by HSNP (helix stabilizing nucleoid protein)-A, HSNP-C, and HSNP-C', show physiologically significant, strong, and synergistic effects in stabilizing duplex DNA against thermal denaturation with Tm increases in the range of 15-30 +/- degrees C.
利用DNA - 纤维素色谱法和羧甲基纤维素色谱法，从嗜酸嗜热古细菌酸热硫化叶菌的类核中纯化出了四种与DNA结合的组蛋白样蛋白，达到了同质纯品。这些蛋白质的分子量在8000 - 12500范围内。免疫印迹结果表明，这些蛋白质中有一些抗原决定簇是共有的，而免疫扩散法无法检测到这些决定簇。已经对这些蛋白质的光谱性质进行了研究。这些蛋白质的氨基酸组成与组蛋白和原核组蛋白样蛋白既有相似之处，也有不同之处。所有这四种蛋白质都以不同的亲和力结合天然和变性的DNA以及单链RNA。其中三种蛋白质，分别命名为HSNP（螺旋稳定类核蛋白）-A、HSNP - C和HSNP - C'，在稳定双链DNA抵抗热变性方面表现出具有生理意义的、强烈的协同效应，使解链温度升高15 - 30±摄氏度。
