Biochemical Characterization of the Subclass B3 Metallo-β-Lactamase PJM-1 from Pseudoxanthomonas japonensis.

Biochemical properties of the novel subclass B3 metallo-β-lactamase (MBL) PJM-1 expressed in Pseudoxanthomonas japonensis, which is often isolated from the environment, were determined. The 906-bp bla PJM-1 gene in P. japonensis is a species-specific MBL gene, and PJM, with 301 predicted amino acids, has 81.8% amino acid identity with AIM-1. In this study, PJM-1 was recombinantly expressed and purified. PJM-1 showed a low catalytic activity against ceftazidime and cefepime, and it was strongly inhibited by EDTA.