The Metallo-b-lactamase GOB Is a Mono-Zn(II) Enzyme with a Novel Active Site

MORAN BARRIO, J; JAVIER M. GONZALEZ, MARIA NATALIA LISA, ALISON L. COSTELLO, MATTEO DAL PERARO, PAOLO CARLONI, BRIAN BENNETT, DAVID L. TIERNEY, ADRIANA S. LIMANSKY, ALEJANDRO M. VIALE, AND ALEJANDRO J. VILA

JOURNAL OF BIOLOGICAL CHEMISTRY

American Society for Biochemistry and Molecular Biology.

Año: 2007 vol. 282 p. 18286 - 18293

0021-9258

Metallo-beta-lactamases (MBLs) are zinc-dependent enzymes able to hydrolyze and inactivate most beta-lactam antibiotics. The large diversity of active site structures and metal content among MBLs from different sources has limited the design of a pan-MBL inhibitor. Here we report the biochemical and biophysical characterization of a novel MBL, GOB-18, from a clinical isolate of a Gram-negative opportunistic pathogen, Elizabethkingia meningoseptica. Different spectroscopic techniques, three-dimensional modeling, and mutagenesis experiments, reveal that the Zn(II) ion is bound to Asp120, His121, His263, and a solvent molecule, in the canonical Zn2 site of dinuclear MBLs. Contrasting all other related MBLs, GOB-18 is fully active against a broad range of beta-lactam substrates using a single Zn(II) ion in this site. These data further enlarge the structural diversity of MBLs.