title: Temperature-dependent variation in the synthesis of streptococcal group-specific carbohydrate. II. Biosynthetic studies in group A and variant strains.
abstract: The biosynthesis of the cell wall polysaccharide and peptidoglycan of group A and A-486-Var streptococci was studied with N-acetyl-[14C]glucosamine, UDP-N-acetyl-[14C]glucosamine, and [14C]glucose. The incorporation of N-acetyl-[14C]-glucosamine into the cell wall four times greater in the A-486-Var cells than in the group A cells. However, the percentage of the total label incorporated into the cell wall polysaccharide at 37 degrees C by the A-486-Var strain was 12%, compared with 66% for the group A cells. When the A-486-Var was grown at 22 degrees C, the proportion of the label incorporated into the cell wall polysaccharide increased to 41%. At 37 degrees C, N-acetyl-[14C]glucosamine was incorporated preferentially into the peptidoglycan of the A-486-Var; almost three times as much of the label was incorporated into the peptidoglycan at 37 degrees C as was incorporated at 22 degrees C. Studies with protoplast membranes of these organisms showed similar differences, with a fourfold greater uptake of UDP-N-acetyl-[14C]glucosamine by the A-486-Var membranes at both incubation temperatures. These studies suggest that a defect in the incorporation of N-acetylglucosamine into the side chain of the polysaccharide is present in the A-486-Var strain at a step following the synthesis of UDP-N-acetylglucosamine. This defect, which may involve the UDP-N-acetylglucosamine transferase, is temperature dependent in the A-486-Var strain.
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism; D017351:N-Acetylglucosaminyltransferases; D010457:Peptidoglycan / Q000096:biosynthesis*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D011523:Protoplasts / Q000201:enzymology; D013297:Streptococcus pyogenes / Q000378:metabolism*; D013696:Temperature; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000378:metabolism
chemical_list: D010457:Peptidoglycan; D011135:Polysaccharides, Bacterial; D014537:Uridine Diphosphate N-Acetylglucosamine; D005964:Glucosyltransferases; D017351:N-Acetylglucosaminyltransferases; C023227:UDP-N-acetylglucosamine transferase; D005947:Glucose; D000117:Acetylglucosamine