REFINED CRYSTAL-STRUCTURE OF PSEUDOAZURIN FROM METHYLOBACTERIUM-EXTORQUENS AM1 AT 1.5-ANGSTROM RESOLUTION

The crystal structure of pseudoazurin from Methylobacterium extorquens AM1 (PAZAM1) has been solved by the molecular replacement method usin g copper-copper distances as translation parameters, which were obtain ed from difference Patterson maps calculated with the synchrotron radi ation data containing the multiwavelength anomalous-dispersion effect. The structure refinement was carried out by the use of molecular dyna mics optimization and the restrained least-squares method. The final c rystallographic R factor was 19.9% for the 14 365 reflections greater than 3sigma between 1.5 and 8.0 angstrom resolution. This report descr ibes the characteristic features of the structure of PAZAM1 as well as the effectiveness of synchrotron radiation for structure analysis of metalloproteins. The environment of the metal active site and the stru ctural differences among blue-copper proteins are discussed.