Enzymatic deacetylation of N-acetylglucosamine residues in cell wall peptidoglycan.
An enzyme which catalyzes the hydrolysis of acetamido groups of N-acetylglucosamine residues in cell wall peptidoglycan was found in the supernatant and 20,000 X g pellet fractions of Bacillus cereus. Autolysis of the latter fraction resulted in solubilization and activation of the deacetylase. Among various bacteria, strains of B. cereus which contain high proportions of N-unsubstituted glucosamine residues in their cell wall peptidoglycan components are particularly rich in the deacetylase. The peptidoglycan deacetylase is distinguishable from N-acetylglucosamine-6-phosphate deacetylase [EC 3.5.1.25] on the basis of their cellular distribution and chromatographic behavior. The rate of reaction of the deacetylase with (N-acetylglucosaminyl-N-acetylmuramic acid)3 [abbreviated as (GlcNAc-MurNAc)3] is less than 1/100 of that with peptidoglycan, while the enzyme is inactive towards (GlcNAc-MurNAc)2, GlcNAc-MurNAc, and monomeric N-acetylglucosamine derivatives. The enzyme also deacetylates partially O-hydroxyethylated chitin. The concentrations of peptidoglycan and partially O-hydroxyethylated chitin required for half-maximum activities were found to be 0.29 and 6.9 mg per ml (or 0.17 and 20 mM with respect to N-acetylglucosamine residues), respectively. The occurrence of this enzyme accounts for the formation of cell wall peptidoglycan N-unsubstituted at the glucosamine residues.
D000117:Acetylglucosamine; D000581:Amidohydrolases / Q000302:isolation & purification / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology; D001409:Bacillus cereus / Q000201:enzymology*; D002473:Cell Wall / Q000032:analysis*; D005944:Glucosamine / Q000031:analogs & derivatives; D007700:Kinetics; D009113:Muramidase / Q000378:metabolism; D010457:Peptidoglycan; D013045:Species Specificity; D013379:Substrate Specificity
D010457:Peptidoglycan; D009113:Muramidase; D000581:Amidohydrolases; C018717:N-acetylglucosamine-6-phosphate deacetylase; D005944:Glucosamine; D000117:Acetylglucosamine