Hendrickson W A, Horton J R, LeMaster D M
Howard Hughes Medical Institute, Columbia University, New York, NY 10032.
EMBO J. 1990 May;9(5):1665-72. doi: 10.1002/j.1460-2075.1990.tb08287.x.
An expression system has been established for the incorporation of selenomethionine into recombinant proteins produced from plasmids in Escherichia coli. Replacement of methionine by selenomethionine is demonstrated at the level of 100% for both T4 and E. coli thioredoxins. The natural recombinant proteins and the selenomethionyl variants of both thioredoxins crystallize isomorphously. Anomalous scattering factors were deduced from synchrotron X-ray absorption measurements of crystals of the selenomethionyl proteins. Taken with reference to experience in the structural analysis of selenobiotinyl streptavidin by the method of multiwavelength anomalous diffraction (MAD), these data indicate that recombinant selenomethionyl proteins analyzed by MAD phasing offer a rather general means for the elucidation of atomic structures.
已经建立了一种表达系统，用于将硒代甲硫氨酸掺入大肠杆菌中由质粒产生的重组蛋白中。对于T4和大肠杆菌硫氧还蛋白，硒代甲硫氨酸替代甲硫氨酸的比例均达到100%。两种硫氧还蛋白的天然重组蛋白和硒代甲硫酰变体均同晶型结晶。通过对硒代甲硫酰蛋白晶体的同步加速器X射线吸收测量推导出反常散射因子。结合通过多波长反常衍射（MAD）方法对硒代生物素化链霉亲和素进行结构分析的经验，这些数据表明，通过MAD定相分析的重组硒代甲硫酰蛋白为阐明原子结构提供了一种相当通用的方法。
