title: Structural Analysis of the Tobramycin and Gentamicin Clinical Resistome Reveals Limitations for Next-generation Aminoglycoside Design.
abstract: Widespread use and misuse of antibiotics has allowed for the selection of resistant bacteria capable of avoiding the effects of antibiotics. The primary mechanism for resistance to aminoglycosides, a broad-spectrum class of antibiotics, is through covalent enzymatic modification of the drug, waning their bactericidal effect. Tobramycin and gentamicin are two medically important aminoglycosides targeted by several different resistance factors, including aminoglycoside 2″-nucleotidyltransferase [ANT(2″)], the primary cause of aminoglycoside resistance in North America. We describe here two crystal structures of ANT(2″), each in complex with AMPCPP, Mn(2+), and either tobramycin or gentamicin. Together these structures outline ANT(2″)'s specificity for clinically used substrates. Importantly, these structures complete our structural knowledge for the set of enzymes that most frequently confer clinically observed resistance to tobramycin and gentamicin. Comparison of tobramycin and gentamicin binding to enzymes in this resistome, as well as to the intended target, the bacterial ribosome, reveals surprising diversity in observed drug-target interactions. Analysis of the diverse binding modes informs that there are limited opportunities for developing aminoglycoside analogs capable of evading resistance.
authors.affiliation: Department of Biochemistry, McGill University , McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 1Y6.|Groupe de Recherche Axé sur la Structure des Protéines, McGill University , Bellini Pavilion, 3649 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 0B1.
authors.forename: Angelia V
authors.initials: AV
authors.lastname: Bassenden
authors.affiliation: Department of Biochemistry, McGill University , McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 1Y6.|Groupe de Recherche Axé sur la Structure des Protéines, McGill University , Bellini Pavilion, 3649 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 0B1.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Rodionov
authors.affiliation: Department of Biochemistry, McGill University , McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 1Y6.|Groupe de Recherche Axé sur la Structure des Protéines, McGill University , Bellini Pavilion, 3649 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 0B1.
authors.forename: Kun
authors.initials: K
authors.lastname: Shi
authors.affiliation: Department of Biochemistry, McGill University , McIntyre Medical Building, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 1Y6.|Department of Microbiology and Immunology, McGill University , Duff Medical Building, 3775 University Street, Montreal, Quebec, Canada , H3A 2B4.|Groupe de Recherche Axé sur la Structure des Protéines, McGill University , Bellini Pavilion, 3649 Promenade Sir William Osler, Montreal, Quebec, Canada , H3G 0B1.
authors.forename: Albert M
authors.initials: AM
authors.lastname: Berghuis
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000617:Aminoglycosides / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D015195:Drug Design; D024881:Drug Resistance, Bacterial; D005839:Gentamicins / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D008345:Manganese / Q000378:metabolism; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D009713:Nucleotidyltransferases / Q000737:chemistry / Q000378:metabolism*; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D014031:Tobramycin / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D005839:Gentamicins; D008345:Manganese; D000255:Adenosine Triphosphate; D009713:Nucleotidyltransferases; C020565:gentamicin 2''-nucleotidyltransferase; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D014031:Tobramycin