title: Peptidoglycan N-acetylglucosamine deacetylation decreases autolysis in Lactococcus lactis.
abstract: The gene xynD (renamed pgdA) of Lactococcus lactis IL1403 was shown to encode a peptidoglycan N-acetylglucosamine deacetylase. Inactivation of pgdA in L. lactis led to fully acetylated peptidoglycan, whereas cloning of pgdA on a multicopy plasmid vector resulted in an increased degree of peptidoglycan deacetylation, as shown by analysis of peptidoglycan constituent muropeptides. An increased amount of N-unsubstituted glucosamine residues in peptidoglycan resulted in a reduction of the rate of autolysis of L. lactis cells. The activity of the L. lactis major autolysin AcmA was tested on L. lactis cells or peptidoglycan with different degrees of de-N-acetylation. Deacetylated peptidoglycan exhibited decreased susceptibility to AcmA hydrolysis. This reduced susceptibility to AcmA did not result from reduced AcmA binding to peptidoglycan with an increasing degree of de-N-acetylation. In conclusion, enzymic N-acetylglucosamine deacetylation protects peptidoglycan from hydrolysis by the major autolysin AcmA in L. lactis cells, and this leads to decreased cellular autolysis.
authors: INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
authors: Mickael
authors: M
authors: Meyrand
authors: INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
authors: Aïda
authors: A
authors: Boughammoura
authors: INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
authors: Pascal
authors: P
authors: Courtin
authors: INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
authors: Christine
authors: C
authors: Mézange
authors: INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
authors: Alain
authors: A
authors: Guillot
authors: INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
authors: Marie-Pierre
authors: MP
authors: Chapot-Chartier
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D000581:Amidohydrolases / Q000235:genetics* / Q000378:metabolism; D001433:Bacteriolysis; D002851:Chromatography, High Pressure Liquid; D017353:Gene Deletion; D013294:Lactococcus lactis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D009113:Muramidase / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D010457:Peptidoglycan / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010457:Peptidoglycan; C092497:AcmA protein, Lactococcus lactis; D009113:Muramidase; D000581:Amidohydrolases; C023079:N-acetylglucosamine deacetylase; D000117:Acetylglucosamine