Romero A, Nar H, Huber R, Messerschmidt A, Kalverda A P, Canters G W, Durley R, Mathews F S
Max-Planck Institut für Biochemie, Abteilung Strukturforschung, Martinsried bei München, Germany.
J Mol Biol. 1994 Mar 4;236(4):1196-211. doi: 10.1016/0022-2836(94)90021-3.
The crystal structure of the type I blue copper protein amicyanin from Thiobacillus versutus has been determined by Patterson search techniques on the basis of the molecular model of amicyanin from Paracoccus denitrificans, and refined by energy-restrained least-squares methods. Amicyanin crystallizes in the trigonal space group P3(2) with unit cell dimensions of a = b = 87.40 A, c = 38.20 A. The asymmetric unit is composed of three independent molecules centred on the crystallographic 3(2) axes. The final R-value is 17.4% for 15,984 reflections to a resolution of 2.15 A. The polypeptide fold in amicyanin is based on the beta-sandwich structure commonly found in blue copper proteins. Nine beta strands are folded into two twisted beta-sheets that pack together with a filling of non-polar residues between them. The geometry of the copper site is similar to that of plastocyanin. There are four ligands, arranged approximately as a distorted tetrahedron, to the copper atom: His54, Cys93, His96 and Met99. One of the copper ligands, His96, is exposed to the surface and lies in the centre of a cluster of seven hydrophobic residues.
运用基于反硝化副球菌中氨腈蓝蛋白分子模型的帕特森搜索技术，已确定了来自活跃硫杆菌的I型蓝铜蛋白氨腈蓝蛋白的晶体结构，并通过能量约束最小二乘法进行了精修。氨腈蓝蛋白以三方空间群P3(2)结晶，晶胞参数为a = b = 87.40 Å，c = 38.20 Å。不对称单元由以晶体学3(2)轴为中心的三个独立分子组成。对于15984个分辨率为2.15 Å的反射，最终R值为17.4%。氨腈蓝蛋白中的多肽折叠基于蓝铜蛋白中常见的β-折叠结构。九条β链折叠成两个扭曲的β-片层，它们相互堆积，中间填充有非极性残基。铜位点的几何结构与质体蓝素相似。有四个配体，大致呈扭曲四面体排列，与铜原子相连：His54、Cys93、His96和Met99。其中一个铜配体His96暴露于表面，位于七个疏水残基簇的中心。
