Chang C H, el-Kabbani O, Tiede D, Norris J, Schiffer M
Biological and Medical Research Division, Argonne National Laboratory, Illinois 60439.
Biochemistry. 1991 Jun 4;30(22):5352-60. doi: 10.1021/bi00236a005.
The structure of the photosynthetic reaction center (RC) from Rhodobacter sphaeroides was determined at 3.1-A resolution by the molecular replacement method, using the Rhodopseudomonas viridis RC as the search structure. Atomic coordinates were refined with the difference Fourier method and restrained least-squares refinement techniques to a current R factor of 22%. The tertiary structure of the RC complex is stabilized by hydrophobic interactions between the L and M chains, by interactions of the pigments with each other and with the L and M chains, by residues from the L and M chains that coordinate to the Fe2+, by salt bridges that are formed between the L and M chains and the H chain, and possibly by electrostatic forces between the ends of helices. The conserved residues at the N-termini of the L and M chains were identified as recognition sites for the H chain.
利用球形红杆菌光合反应中心（RC）作为搜索结构，通过分子置换法以3.1埃分辨率确定了球形红杆菌光合反应中心的结构。原子坐标采用差值傅里叶法和约束最小二乘精修技术进行精修，目前的R因子为22%。RC复合物的三级结构通过L链和M链之间的疏水相互作用、色素之间以及色素与L链和M链之间的相互作用、L链和M链中与Fe2+配位的残基、L链和M链与H链之间形成的盐桥以及可能存在的螺旋末端之间的静电力得以稳定。L链和M链N端的保守残基被确定为H链的识别位点。
