A Metabolic Relationship Between the Aromatic Amino Acids

The present work involves a further investigation of a Neurospora mutant, C-86, previously mentioned by Lein, Mitchell and Houlahan (1) as one that can utilize anthranilic acid, indole, tryptophan, kynurenine, 3-hydroxyanthranilic acid, and nicotinic acid as supplements for growth. Mutant C-86, when crossed to a “wild-type” strain, was found to differ from this wild type strain, with respect to tryptophan biosynthesis, by a mutation at a single locus. The evidence presented suggests the possibility of a common precursor to the aromatic amino acids