Mutational Effects on Carbapenem Hydrolysis of YEM-1, a New Subclass B2 Metallo-β-Lactamase from Yersinia mollaretii.

Analysis of the genome sequence of ATCC 43969 identified the gene, encoding YEM-1, a putative subclass B2 metallo-β-lactamase. The objectives of our work were to produce and purify YEM-1 and to complete its kinetic characterization. YEM-1 displayed the narrowest substrate range among known subclass B2 metallo-β-lactamases, since it can hydrolyze imipenem, but not other carbapenems, such as biapenem, meropenem, doripenem, and ertapenem, with high catalytic efficiency.