title: Activation of inhibitors by sortase triggers irreversible modification of the active site.
abstract: Sortases anchor surface proteins to the cell wall of Gram-positive pathogens through recognition of specific motif sequences. Loss of sortase leads to large reductions in virulence, which identifies sortase as a target for the development of antibacterials. By screening 135,625 small molecules for inhibition, we report here that aryl (beta-amino)ethyl ketones inhibit sortase enzymes from staphylococci and bacilli. Inhibition of sortases occurs through an irreversible, covalent modification of their active site cysteine. Sortases specifically activate this class of molecules via beta-elimination, generating a reactive olefin intermediate that covalently modifies the cysteine thiol. Analysis of the three-dimensional structure of Bacillus anthracis sortase B with and without inhibitor provides insights into the mechanism of inhibition and reveals binding pockets that can be exploited for drug discovery.
authors.affiliation: Department of Microbiology, University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Maresso
authors.forename: Ruiying
authors.initials: R
authors.lastname: Wu
authors.forename: Justin W
authors.initials: JW
authors.lastname: Kern
authors.forename: Rongguang
authors.initials: R
authors.lastname: Zhang
authors.forename: Dorota
authors.initials: D
authors.lastname: Janik
authors.forename: Dominique M
authors.initials: DM
authors.lastname: Missiakas
authors.forename: Mark-Eugene
authors.initials: ME
authors.lastname: Duban
authors.forename: Andrzej
authors.initials: A
authors.lastname: Joachimiak
authors.forename: Olaf
authors.initials: O
authors.lastname: Schneewind
mesh_terms: D000475:Alkenes / Q000737:chemistry; D019881:Aminoacyltransferases / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology*; D001408:Bacillus anthracis / Q000201:enzymology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology*; D001665:Binding Sites; D003545:Cysteine / Q000737:chemistry; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology*; D004229:Dithiothreitol / Q000494:pharmacology; D015195:Drug Design; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000737:chemistry; D020128:Inhibitory Concentration 50; D007659:Ketones; D007700:Kinetics; D008954:Models, Biological; D011487:Protein Conformation
chemical_list: D000475:Alkenes; D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D007659:Ketones; C509821:sortase B; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases; D003545:Cysteine; D004229:Dithiothreitol