Disease relevance of trpR

• Salmonella typhimurium prototrophs carrying a trpR mutation synthesize tryptophan biosynthetic enzymes constitutively [1].
• To clone trpR homologues, a deletion of the E. coli trpR gene, delta trpR504, was made on a plasmid by site-directed mutagenesis, then crossed onto the E. coli genome [2].
• The conservation of trp operator sequences among enteric Gram-negative bacteria suggests that trpR genes from other bacterial species can be cloned by complementation in E. coli [2].

High impact information on trpR

• Strains with LT7-derived trp genes bearing a deletion in trpA produced tryptophan as readily as LT2 trpR prototrophs [1].
• When feedback inhibition of anthranilate synthetase but not 5'-phosphoribosylpyrophosphate phosphoribosyltransferase activity was by-passed by growing cells on media supplemented with anthranilic acid, all trpR prototrophs overproduced and excreted tryptophan [1].
• Tn10 insertions near pnuA, pnuC and pnuD were isolated and utilized in mapping studies. pnuA was found to map between thr and serB near trpR [3].

References