Purification, crystallization and preliminary X-ray analysis of IMP-18, a class B carbapenemase from Pseudomonas aeruginosa

Class B β-lactamases are known as metallo-β-lactamases (MBLs) and they hydrolyze most β-lactams, including carbapenems. IMP-18, an MBL cloned from Pseudomonas aeruginosa, was overexpressed, purified and crystallized by vapour diffusion for X-ray crystallographic analysis. Preliminary X-ray analysis showed that the crystal diffracted to 2.4 Å resolution and belonged to the tetragonal space group P4₁2₁2, with unit-cell parameters a = b = 120.77, c = 96.54 Å, α = β = γ = 90°, suggesting the presence of two molecules in the asymmetric unit.