title: Insights into an evolutionary strategy leading to antibiotic resistance.
abstract: Metallo-β-lactamases (MBLs) with activity towards a broad-spectrum of β-lactam antibiotics have become a major threat to public health, not least due to their ability to rapidly adapt their substrate preference. In this study, the capability of the MBL AIM-1 to evade antibiotic pressure by introducing specific mutations was probed by two alternative methods, i.e. site-saturation mutagenesis (SSM) of active site residues and in vitro evolution. Both approaches demonstrated that a single mutation in AIM-1 can greatly enhance a pathogen's resistance towards broad spectrum antibiotics without significantly compromising the catalytic efficiency of the enzyme. Importantly, the evolution experiments demonstrated that relevant amino acids are not necessarily in close proximity to the catalytic centre of the enzyme. This observation is a powerful demonstration that MBLs have a diverse array of possibilities to adapt to new selection pressures, avenues that cannot easily be predicted from a crystal structure alone.
authors.affiliation: Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia.
authors.forename: Chun-Feng D
authors.initials: CD
authors.lastname: Hou
authors.affiliation: CSIRO Entomology, Black Mountain, ACT 2601, Australia.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Liu
authors.affiliation: School of Molecular Bioscience, The University of Sydney, NSW 2006, Australia.
authors.forename: Charles
authors.initials: C
authors.lastname: Collyer
authors.affiliation: Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland.
authors.forename: Nataša
authors.initials: N
authors.lastname: Mitić
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Marcelo Monteiro
authors.initials: MM
authors.lastname: Pedroso
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schenk
authors.affiliation: Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Ollis
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D055162:Biocatalysis / Q000187:drug effects; D005075:Biological Evolution; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D019020:Directed Molecular Evolution; D004352:Drug Resistance, Microbial; D005818:Genetic Engineering; D008826:Microbial Sensitivity Tests; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D013379:Substrate Specificity / Q000187:drug effects; D047090:beta-Lactams / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams