title: Dual Mode of Action for Plusbacin A3in Staphylococcus aureus.
abstract: We have used C{F}, N{F}, and N{P} rotational-echo double resonance NMR to determine the location and conformation of19F and15N double-labeled plusbacin A3and of double-labeled deslipo-plusbacin A3, each bound to the cell walls of whole cells of Staphyloccocus aureus grown in media containing [1-13C]glycine. The31P is primarily in wall teichoic acid. Approximately 25% of plusbacin headgroups (the cyclic depsipeptide backbone) are in a closed conformation (N-F separation of 6 Å), while 75% are in a more open conformation (N-F separation of 12 Å). The closed headgroups have no contact with wall teichoic acid, whereas the open headgroups have a strong contact. This places the closed headgroups in hydrophobic regions of the cell wall and the open headgroups in hydrophilic regions. None of the plusbacin tails have contact with the31P of either wall teichoic acid or the cell membrane and thus are in hydrophobic regions of the cell wall. In addition, both heads and tails of plusbacin A3have contact with the glycyl13C incorporated in cell-wall peptidoglycan pentaglycyl bridges and with13C-labeled purines near the membrane surface. We interpret these results in terms of a dual mode of action for plusbacin A3: first, disruption of the peptidoglycan layer nearest to the membrane surface by closed-conformation plusbacin A3leading to an inhibition of chain extension by transglycosylation; second, thinning and disruption of the membrane (possibly including disruption of ATP-binding cassette transporters embedded in the membrane) by open-conformation plusbacin A3, thereby leading to release of ATP to the hydrophilic regions of the cell wall and subsequent binding by plusbacin A3.
authors.affiliation: Department of Chemistry, Washington University , St. Louis, Missouri 63130, United States.
authors.forename: Robert D
authors.initials: RD
authors.lastname: O'Connor
authors.affiliation: Department of Chemistry, Washington University , St. Louis, Missouri 63130, United States.
authors.forename: Manmilan
authors.initials: M
authors.lastname: Singh
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76798, United States.
authors.forename: James
authors.initials: J
authors.lastname: Chang
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76798, United States.
authors.forename: Sung Joon
authors.identifier: 0000-0002-2007-6606
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: VanNieuwenhze
authors.affiliation: Department of Chemistry, Washington University , St. Louis, Missouri 63130, United States.
authors.forename: Jacob
authors.identifier: 0000-0002-7544-6408
authors.initials: J
authors.lastname: Schaefer
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D002473:Cell Wall / Q000737:chemistry*; D047630:Depsipeptides / Q000737:chemistry*; D003903:Deuterium; D005462:Fluorine Radioisotopes; D057927:Hydrophobic and Hydrophilic Interactions; D008968:Molecular Conformation; D009590:Nitrogen Radioisotopes; D010457:Peptidoglycan / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D047630:Depsipeptides; D005462:Fluorine Radioisotopes; D009590:Nitrogen Radioisotopes; D010457:Peptidoglycan; C433785:plusbacin A3; D003903:Deuterium