Tepliakov A V, Kuranova I P, Arutiunian E G, Frömmel C, Höhne W E
Bioorg Khim. 1990 Apr;16(4):437-47.
Crystal structure of thermitase, a serine proteinase from Thermoactinomyces vulgaris, has been determined by X-ray diffraction at 1.4 A resolution. The atomic model of thermitase refined to an R-factor of 0.149 contains 1997 protein atoms, 182 water molecules and 2 Ca2+ ions. The tertiary structure of thermitase is similar to that of subtilisin BPN'. The greatest variations are connected with insertions and deletions in the amino acid sequence, which are located on the surface of the molecule. Higher thermostability of thermitase can be explained in terms of the three-dimensional structure. The Ca2+ ions, bound to the protein molecule, as well as the ionic and hydrophobic interactions are supposed to give the main contribution to the stabilization of the structure.
嗜热栖热放线菌丝氨酸蛋白酶嗜热酶的晶体结构已通过X射线衍射在1.4埃分辨率下测定。精修至R因子为0.149的嗜热酶原子模型包含1997个蛋白质原子、182个水分子和2个Ca2+离子。嗜热酶的三级结构与枯草杆菌蛋白酶BPN'相似。最大的差异与位于分子表面的氨基酸序列中的插入和缺失有关。嗜热酶较高的热稳定性可以从三维结构方面进行解释。与蛋白质分子结合的Ca2+离子以及离子和疏水相互作用被认为对结构的稳定起主要作用。
