PMID:4904235

Citation	Held, WA and Smith, OH (1970) Mechanism of 3-methylanthranilic acid derepression of the tryptophan operon in Escherichia coli. J. Bacteriol. 101:209-17
Abstract	3-Methylanthranilic acid (3MA) inhibits growth and causes derepression of the tryptophan biosynthetic enzymes in wild-type strains of Escherichia coli. Previous reports attributed this effect to an inhibition of the conversion of 1-(o-carboxyphenylamino)-1-deoxyribulose 5-phosphate to indole-3-glycerol phosphate and a consequent reduction in the concentration of endogenous tryptophan. Our studies have shown that 3MA-resistant mutants linked to the tryptophan operon have a feedback-resistant anthranilate synthetase; mutants with an altered indole-3-glycerol phosphate synthetase were not found. 3MA or 7-methylindole can be metabolized to 7-methyltryptophan, and 3MA, 7-methylindole, and 7-methyltryptophan lead to derepression of the tryptophan operon. Furthermore, 3MA-resistant mutants are also resistant to 7-methylindole derepression. These results strongly suggest that the primary cause of derepression by 3MA is through its conversion to 7-methyltryptophan, which can inhibit anthranilate synthetase, thereby decreasing the concentration of endogenous tryptophan. Unlike 5- or 6-methyltryptophan, 7-methyltryptophan does not appear to function as an active corepressor.
Links	PubMed PMC250472
Keywords	Anthranilic Acids/analysis; Anthranilic Acids/metabolism; Culture Media; Enzyme Repression/drug effects; Escherichia coli/enzymology; Escherichia coli/growth & development; Glycerol/metabolism; Indoles/metabolism; Kinetics; Ligases; Molecular Biology; Mutation; Operon; Pentoses/metabolism; Phosphates/metabolism; Tritium; Tryptophan/biosynthesis; Tryptophan/metabolism
edit table

Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).

Phenotype Annotations

See Help:AnnotationTable for details on how to edit this table.
<protect>

Phenotype of	Taxon Information	Genotype Information (if known)	Condition Information	OMP ID	OMP Term Name	ECO ID	ECO Term Name	Notes	Status
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: W1485 tna NCBI Taxon ID: 83333	Genotype of Reference Strain: trpE+ Genotype of Experimental Strain : trpEFBR 2-50	Reference Condition:					Mutation to the trpE gene conferred resistance toward anthranilate synthetase. This was also seen in strain trpEFBR1-42. See Table 1.
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: W1485 tna NCBI Taxon ID: 83333	Genotype of Reference Strain: trpE+ Genotype of Experimental Strain : MAR mutation in trpE gene.	Reference Condition:					MAR mutation to the trpE gene conferred resistance toward anthranilate synthetase in MAR 13. This was also seen in strains MAR 1-9, MAR 31' and MAR 22. See Table 1.
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: W1485 tna NCBI Taxon ID: 83333	Genotype of Reference Strain: trpE+ - trpR+ Genotype of Experimental Strain : trpR trpEFBR44	Reference Condition:					The trpR mutation and trpEFBR double mutations conferred resistance toward anthranilate synthetase mutants. This was seen in strains trpR-trpEFBR46 See table 1.
edit table

</protect>

References

See Help:References for how to manage references in omp dev.