Inoue T, Gotowda M, Kataoka K, Yamaguchi K, Suzuki S, Watanabe H, Gohow M, Kai Y
Department of Materials Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan.
J Biochem. 1998 Nov;124(5):876-9. doi: 10.1093/oxfordjournals.jbchem.a022201.
The crystal structure of the blue nitrite reductase from Alcaligenes xylosoxidans GIFU 1051 (AxgNIR) has been determined at 2.05 A resolution. AxgNIR contains both type 1 and 2 Cu sites, the geometry of the former being distorted tetrahedral. The superpositioning of the type 1 Cu sites in the blue enzyme and a green nitrite reductase revealed that the orientation of the Met150 side chain differed. The deviation of the Sdelta(Met150) atom from the axial position of the NNS plane formed by two Ndelta(His95 and His145) and one Sgamma(Cys136) atom caused the difference in the colors of the enzymes, i.e. blue and green.
嗜木产碱菌GIFU 1051（AxgNIR）蓝色亚硝酸还原酶的晶体结构已在2.05埃分辨率下测定。AxgNIR同时含有1型和2型铜位点，前者的几何结构为扭曲的四面体。蓝色酶和绿色亚硝酸还原酶中1型铜位点的叠加显示，Met150侧链的取向不同。Met150的Sδ原子偏离由两个Nδ（His95和His145）和一个Sγ（Cys136）原子形成的NNS平面的轴向位置，导致了酶颜色的差异，即蓝色和绿色。
