Interactions ofYersinia pestisPenicillin-Binding Proteins with b-Lactam Antibiotics†

The affinities of six major penicillin-binding proteins (PBPs) of Yersinia pestis EV76 to different b-lactam antibiotics were determined. The results indicate that, similar to their counterparts inEscherichia coli, PBP2 and PBP3 are the lethal targets of amdinocillin and furazlocillin, respectively. The PBP contents of four additional Y. pestis strains and the morphological effects produced by some b-lactam antibiotics are also reported. Penicillin-binding proteins (PBPs) are bacterial cytoplasmic membrane proteins involved in the last steps of peptidoglycan synthesis and are the lethal targets of b-lactam antibiotics (10‐12).Penicillin,beingastructuralanalogoftheacyl-D-Ala‐