Crystal structure of an alkaline protease from Bacillus alcalophilus at 2.4Åresolution

Abstract
The crystal structure of an alkaline protease from Bacillus alcahphilus has been determined by X‐ray diffraction at 2.4Åresolution. The enzyme crystallizes in space group P212121, with lattice constants a = 53.7, b = 61.6, c = 75.9Å. The structure was solved by molecular replacement using the structure of subtilisin Carlsberg as search model. Refinement using molecular dynamics and restrained least squares methods results in a crystallographic R‐factor of 0.185. The tertiary structure is very similar to that of subtilisin Carlsberg. The greatest structural differences occur in loops at the surface of the protein.