Disease relevance of trpA

• The discovery of this strain difference has particular implications for studies involving the activities of trpA and B genes and their products in S. typhimurium and may have general significance for other studies involving different strains of Salmonella [1].

High impact information on trpA

• The molecular characterization of the mutation that corrected the Eut- phenotype caused by allele Delta903 showed that the new mutation was a deletion of two nucleotides at the tonB-trpA fusion site [2].
• The level of trpA protein production depended on the particular insert and the plasmid used [3].
• Mitomycin C, a compound that induces colicin E1 production in ColE1-containing bacteria, stimulated tryptophan synthetase alpha production in cells containing ColE1-TRPA plasmids with the trpA fragment inserted in one orientation but not the other [4].
• Strains with LT7-derived trp genes bearing a deletion in trpA produced tryptophan as readily as LT2 trpR prototrophs [1].
• Among a group of 5-methyltryptophan (MT) resistant derivatives of trpA mutants we encountered several with a novel phenotype: they actually grew better in the presence of MT than in its absence [5].

Biological context of trpA

• The trpA fragment inserted into EcoRI-cleaved plasmids ColE1 and CR1 was expressed regardless of its orientation of insertion [4].
• The protein product of trpA, the first structural gene of the operon, appears to have been partially damaged by the re-initiation event in at least two strains, while in the other strains, the enzyme appears in preliminary tests to be indistinguishable from that of wild type [6].

Associations of trpA with chemical compounds

• This indicated that LT7-specific 5-phosphoribosylpyrophosphate phosphoribosyltransferase must be aggregated with the trpA gene produce to give an observable reduction of constitutive tryptophan production [1].

References