Crystallization and preliminary X-ray analysis of the subclass B3 metallo-β-lactamase SMB-1 that confers carbapenem resistance

The carbapenem-hydrolyzing subclass B3 metallo-β-lactamase SMB-1 was expressed in Escherichia coli and purified. Diffraction data were collected from two types of SMB-1 crystals that were obtained under different conditions. One crystal (SMB-1a) belonged to the trigonal space group P31 with unit-cell parameters a = b = 67.83, c = 48.67 Å, while the other crystal (SMB-1b) also belonged to space group P3 ₁ but with unit-cell parameters a = b = 67.25, c = 46.83 Å. Both crystals contained one molecule per asymmetric unit. Initial phases were determined by molecular replacement; further refinement and model building are in progress.