Biosynthesis of the K99 surface antigen is repressed by alanine.
The amino acid alanine induced a direct and specific repression of the biosynthesis of the K99 surface antigen in Escherichia coli strains harboring the K99 plasmid. In minimal medium with 0.5% glucose, 1 mM L-alanine was sufficient to reduce the K99 production by about 95%. The low production of the K99 antigen by strains growing on commercially available nutrient media seemed to be a result of the inhibitory effect alanine on the K99 biosynthesis.
D000409:Alanine / Q000494:pharmacology*; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D004926:Escherichia coli / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D007700:Kinetics
D000942:Antigens, Bacterial; D000954:Antigens, Surface; D000409:Alanine