Green G R, Searcy D G, DeLange R J
Biochim Biophys Acta. 1983 Nov 17;741(2):251-7. doi: 10.1016/0167-4781(83)90066-0.
The Archaebacterium Thermoplasma acidophilum contains a basic chromosomal protein remarkably similar to the histones of eukaryotes. Therefore, it was of interest to examine a different Archaebacterium for similar proteins. We chose to examine Sulfolobus acidocaldarius because it is thermophilic, like T. acidophilum, but nevertheless the two organisms are not particularly closely related. Two major chromosomal proteins were found in S. acidocaldarius. The smaller of these was soluble in 0.2 M H2SO4 and had a molecular weight of 14500. The larger was acid-insoluble and had a molecular weight of about 36000. Together, the proteins protected about 5% of the DNA against nuclease digestion and stabilized about 50% against thermal denaturation. Overall, the properties of these proteins were intermediate between those of the Escherichia coli protein HU and T. acidophilum protein HTa.
嗜酸性嗜热放线菌含有一种碱性染色体蛋白，与真核生物的组蛋白非常相似。因此，研究另一种古细菌中是否存在类似蛋白质很有意义。我们选择研究嗜酸热硫化叶菌，因为它和嗜酸性嗜热放线菌一样嗜热，但这两种生物的亲缘关系并不特别密切。在嗜酸热硫化叶菌中发现了两种主要的染色体蛋白。其中较小的一种可溶于0.2M硫酸，分子量为14500。较大的一种不溶于酸，分子量约为36000。这两种蛋白质共同保护约5%的DNA不被核酸酶消化，并使约50%的DNA免受热变性影响。总体而言，这些蛋白质的特性介于大肠杆菌蛋白HU和嗜酸性嗜热放线菌蛋白HTa之间。
