Peptidoglycan N-acetylglucosamine deacetylation decreases autolysis in Lactococcus lactis.
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.
Meyrand
Mickael
M
INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
Boughammoura
Aïda
A
INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
Courtin
Pascal
P
INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
Mézange
Christine
C
INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
Guillot
Alain
A
INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
Chapot-Chartier
Marie-Pierre
MP
INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France.
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
D010457:Peptidoglycan; C092497:AcmA protein, Lactococcus lactis; D009113:Muramidase; D000581:Amidohydrolases; C023079:N-acetylglucosamine deacetylase; D000117:Acetylglucosamine