Crystallographic Study of Mutants and Complexes of Oligopeptidase B from Serratia proteamaculans

The results of the structural studies of bacterial oligopeptidase B (OpB) belonging to the least well-studied prolyl oligopeptidase family are described. The screening of crystallization conditions for mutants of the enzyme, its complexes with peptides, which mimic substrates and catalytic reaction products, and a complex with a transition state analog as an inhibitor was performed in order to determine the three-dimensional structures of OpB from Serratia proteamaculans (PSP) acting at different steps of the catalytic cycle. Crystals suitable for X-ray diffraction were grown. The X-ray diffraction data sets were collected, processed, and subjected to preliminary analysis. These X-ray diffraction data sets are suitable for obtaining the structural data necessary for the description of the catalytic cycle of bacterial ОpBs.