A Crystallographic Workbench and Its Use in Structure Analysis of Hydrogenase

开发了一种安装有软件包和数据库系统的结晶学工作台或结晶学工作站，可以实现从X射线测量到蛋白质结构分析的一条龙处理。随着工作站在许多结晶学实验室中变得越来越普遍，现在可以通过局域网构建直通X射线分析系统。利用X射线衍射仪、Rigaku四圆单晶衍射仪和MAC Science Image构建了一个从任意晶体样品测量X射线强度、通过网络传输结构因子数据、进行结构分析和显示分子结构的集成系统。基于五个重原子衍生物的电子密度图显示了四个与蛋白质区明显区别的强峰。用差分傅立叶技术，用多重同晶置换(MIR)方法计算了三个铁硫原子团和一个镍原子的最强密度，并利用同步辐射光源获得了五个波长(1.040，1.487，1.730，1.743和1.750*)的结构因子。四个活性中心以大约13*的距离排列在一起，这似乎是合理的，它们与电子转移链相连。

A crystallographic workbench or a crystallographic workstation installed with software packages and database systems is developed, which enables a through processing from X-ray measurement to protein structure analysis. As workstations have become more popular in many crystallography laboratories, a through X-ray analysis system is now able to be constructed via local area network. X-ray diffraction measurement apparatuses, Rigaku fourcircle single crystal diffractometer and MAC Science Image The construction of an integrated system of measuring the X-ray intensities from any crystal specimen, transferring structure factor data via network, carrying out the structure analysis and displaying the molecular structure.The active centers of NiFe hydrogenase from Desulfovibrio vulgaris Miyazaki F has been located in the electron density map calculated at 4 * resolution. The electron density map based on five heavy atom derivatives showed four strong peaks which were clearly distinguished from the protein region. These strong densities have been successfully assigned to three iron-sulfur clusters and one nickel atom by difference Fourier technique with coefficients of the best phases from multiple isomorphous replacement (MIR) method and structure factors obtained at five wavelengths (1.040,1.487,1.730,1.743, and 1.750* with use of the synchrotron radiation source. Four active centers are approximately lined up with a distance of ca. 13* which seems to be reasonable for them to be connected with electron transfer chain.