A Crystallographic Workbench and Its Use in Structure Analysis of Hydrogenase

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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.