Regulation of L-arabinose transport in Salmonella typhimurium LT2.
The inducible L-arabinose transport system was characterized in Salmonella typhimurium LT2. Only one L-arabinose transport system with a Km of 2 X 10(-4) M was identified. The results suggested that araE may be the only gene which codes for L-arabinose transport activity under the conditions tested. An araE-lac fusion strain was used to study the induction of the araE gene. No araE expression was detected when the L-arabinose concentration was lower than 1 mM. The expression of araE reached a maximum in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of 50 mM L-arabinose, and was significantly reduced in the presence of D-glucose. Expression of the araBAD and araE genes was coordinately regulated. The concentration of L-arabinose that allowed maximum araBAD gene expression was 50-fold lower in an araE+ strain compared to an araE strain.
D001089:Arabinose / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis; D001692:Biological Transport; D000242:Cyclic AMP / Q000494:pharmacology; D005786:Gene Expression Regulation; D005796:Genes; D005809:Genes, Regulator; D005947:Glucose / Q000494:pharmacology; D007700:Kinetics; D009005:Monosaccharides / Q000494:pharmacology; D009876:Operon; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D009005:Monosaccharides; D001089:Arabinose; D000242:Cyclic AMP; D005947:Glucose