title: The metallo-beta-lactamase GOB is a mono-Zn(II) enzyme with a novel active site.
abstract: 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.
authors.affiliation: Departamento de Química Biológica and Departamento de Microbiología, Instituto de Biología Molecular y Celular de Rosario (IBR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
authors.forename: Jorgelina
authors.initials: J
authors.lastname: Morán-Barrio
authors.affiliation: Departamento de Química Biológica and Departamento de Microbiología, Instituto de Biología Molecular y Celular de Rosario (IBR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
authors.forename: Javier M
authors.initials: JM
authors.lastname: González
authors.affiliation: Departamento de Química Biológica and Departamento de Microbiología, Instituto de Biología Molecular y Celular de Rosario (IBR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
authors.forename: María Natalia
authors.initials: MN
authors.lastname: Lisa
authors.affiliation: Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Costello
authors.affiliation: Center for Molecular Modeling, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Matteo Dal
authors.initials: MD
authors.lastname: Peraro
authors.affiliation: International School for Advanced Studies, Via Beirut 2-4, 34100 Trieste, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Carloni
authors.affiliation: National Biomedical EPR Center, Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-0509.
authors.forename: Brian
authors.initials: B
authors.lastname: Bennett
authors.affiliation: Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131.
authors.forename: David L
authors.initials: DL
authors.lastname: Tierney
authors.affiliation: Departamento de Química Biológica and Departamento de Microbiología, Instituto de Biología Molecular y Celular de Rosario (IBR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Limansky
authors.affiliation: Departamento de Química Biológica and Departamento de Microbiología, Instituto de Biología Molecular y Celular de Rosario (IBR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
authors.forename: Alejandro M
authors.initials: AM
authors.lastname: Viale
authors.affiliation: Departamento de Química Biológica and Departamento de Microbiología, Instituto de Biología Molecular y Celular de Rosario (IBR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, Argentina. Electronic address: vila@ibr.gov.ar.
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Vila
mesh_terms: D001665:Binding Sites; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry; D005417:Flavobacterium / Q000378:metabolism; D005822:Genetic Vectors; D006868:Hydrolysis; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016297:Mutagenesis, Site-Directed; D013053:Spectrophotometry; D015032:Zinc / Q000737:chemistry*; D001618:beta-Lactamases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
chemical_list: D004247:DNA; D001618:beta-Lactamases; D015032:Zinc