Evidence for an Interrelation in the Metabolism of Lysine, Arginine and Pyramidines in Neurospora

Abstract

Of 4 non-allelic lysineless strains 2 have been shown to accumulate pyrimidines, while 2 do not. One of the accumulated compounds has been isolated and identified as uridine. The double and triple mutant combinations of the pyrimidineless gene, 3a and its suppressor, s, with 2 lysineless strains have been prepd. and tested. Several of these show growth responses, not characteristic of the single mutants involved, which indicate a relationship in the metabolism of pyrimidineless, lysine and arginine. Combination of the genes, lysineless 3, pyrimidineless 3a and s introduces a requirement for arginine. Lysineless strain 1 is able to use alpha amino adipic acid, unless arginine, citrulline or ornithine is also supplied. By combination of this lysineless gene with pyrimidineless 3a a strain is produced which cannot use alpha amino adipic acid unless a small amt. of lysine is added.