The Metallo-beta-lactamase GOB is a mono-Zn(II) enzyme with a novel active site

MORAN BARRIO, J; GONZALEZ, J; LISA, M N; COSTELLO, A; DAL PERARO, M; CARLONI, P; BENNET, B; TIERNEY, D; LIMANSKY, A S; VIALE, A M; VILA, A J

JOURNAL OF BIOLOGICAL CHEMISTRY

American Society for Biochemistry and Molecular Biology

Lugar: United States; Año: 2007 vol. 282 p. 18286 - 18293

0021-9258

Metallo-beta-lactamases (MbetaLs) are zinc-dependent enzymes able to hydrolyze and inactivate most beta-lactam antibiotics. The large diversity of active site structures and metal content among MbetaLs from different sources has limited the design of a pan-MbetaL inhibitor. Here we report the biochemical and biophysical characterization of a novel MbetaL, 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, i.e. in the canonical Zn2 site of dinuclear MbetaLs. Contrasting all other related MbetaLs, 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 MbetaLs.