Refined crystal structure of pseudoazurin from Methylobacterium extorquens AM1 at 1.5 Å resolution

The crystal structure of pseudoazurin from Methylobacterium extorquens AM1 (PAZAM1) has been solved by the molecular replacement method using copper–copper distances as translation parameters, which were obtained from difference Patterson maps calculated with the synchrotron radiation data containing the multiwavelength anomalous-dispersion effect. The structure refinement was carried out by the use of molecular dynamics optimization and the restrained least-squares method. The final crystallographic R factor was 19.9% for the 14 365 reflections greater than 3σ between 1.5 and 8.0 Å resolution. This report describes the characteristic features of the structure of PAZAM 1 as well as the effectiveness of synchrotron radiation for structure analysis of metalloproteins. The environment of the metal active site and the structural differences among blue-copper proteins are discussed.