Housset D, Habersetzer-Rochat C, Astier J P, Fontecilla-Camps J C
Laboratoire de Cristallographie et Cristallogenèse des Protéines Institut de Biologie Structurale, Grenoble, France.
J Mol Biol. 1994 Apr 22;238(1):88-103. doi: 10.1006/jmbi.1994.1270.
The crystal structure of toxin II from the scorpion Androctonus australis Hector has been refined at 1.3 A resolution using restrained least-squares methods. The final R-factor is 0.148 for the 13,619 reflections between 7.0 A and 1.3 A resolution with F > 2.5 sigma (F) and the bond length standard deviation from ideality is 0.017 A. Although minor changes have been introduced relative to the model previously refined at 1.8 A resolution, the use of higher-resolution data has allowed the modelling of some discrete disorder. Thus, three residues (including a disulphide bridge) have been built with multiple conformations. Occupancies were refined for the 106 solvent molecules included in the model, nine of them with explicit multiple sites. There is well-defined electron density for some of the protein hydrogen atoms in the final difference Fourier map. A detailed description of the toxin structure is presented, along with a comparison with the high-resolution structure of the related variant-3 scorpion toxin.
采用约束最小二乘法，已将澳大利亚杀人蝎（Androctonus australis Hector）毒素II的晶体结构精修至1.3 Å分辨率。对于7.0 Å至1.3 Å分辨率之间的13,619个反射（F > 2.5σ(F)），最终R因子为0.148，键长与理想值的标准偏差为0.017 Å。尽管相对于之前在1.8 Å分辨率下精修的模型有一些微小变化，但使用更高分辨率的数据使得能够对一些离散无序进行建模。因此，三个残基（包括一个二硫键）构建了多种构象。对模型中包含的106个溶剂分子的占有率进行了精修，其中9个具有明确的多个位点。在最终的差值傅里叶图中，一些蛋白质氢原子有明确的电子密度。本文给出了毒素结构的详细描述，并与相关变体3蝎毒素的高分辨率结构进行了比较。
