title: Selectivity for D-lactate incorporation into the peptidoglycan precursors of Lactobacillus plantarum: role of Aad, a VanX-like D-alanyl-D-alanine dipeptidase.
abstract: Lactobacillus plantarum produces peptidoglycan precursors ending in D-lactate instead of D-alanine, making the bacterium intrinsically resistant to vancomycin. The ligase Ddl of L. plantarum plays a central role in this specificity by synthesizing D-alanyl-D-lactate depsipeptides that are added to the precursor peptide chain by the enzyme MurF. Here we show that L. plantarum also encodes a D-Ala-D-Ala dipeptidase, Aad, which eliminates D-alanyl-D-alanine dipeptides that are produced by the Ddl ligase, thereby preventing their incorporation into the precursors. Although D-alanine-ended precursors can be incorporated into the cell wall, inactivation of Aad failed to suppress growth defects of L. plantarum mutants deficient in d-lactate-ended precursor synthesis.
authors.affiliation: Unité de Génétique, Institut des Sciences de la Vie, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium.
authors.forename: Marie
authors.initials: M
authors.lastname: Deghorain
authors.forename: Philippe
authors.initials: P
authors.lastname: Goffin
authors.forename: Laetitia
authors.initials: L
authors.lastname: Fontaine
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Mainardi
authors.forename: Richard
authors.initials: R
authors.lastname: Daniel
authors.forename: Jeff
authors.initials: J
authors.lastname: Errington
authors.forename: Bernard
authors.initials: B
authors.lastname: Hallet
authors.forename: Pascal
authors.initials: P
authors.lastname: Hols
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D001692:Biological Transport / Q000187:drug effects; D004150:Dipeptidases / Q000235:genetics / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism*; D048191:Lactiplantibacillus plantarum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D010457:Peptidoglycan / Q000378:metabolism*; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D010457:Peptidoglycan; D019344:Lactic Acid; D014640:Vancomycin; D004150:Dipeptidases; C038937:dipeptidase