Evolution of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase-encoding genes in the yeast Saccharomyces cerevisiae.

ABSTRACT: The shikimate pathway resulting in three aromatic amino acids is initiated in different organisms by two and three 3-deoxy-d-arabino-heptulosonate-7-phosphate synthases, respectively. Aro3p and Aro4p are the yeast enzymes feedback-inhibited by phenylalanine and tyrosine, respectively. A yeast strain deficient in the general control transcriptional regulatory system of amino acid biosynthesis is unable to live in the presence of high amounts of phenylalanine and tyrosine. Here, we show that this yeast strain can be rescued by the expression of aroH from Escherichia coli encoding the tryptophan-regulated AroH as third isoenzyme. Yeast carrying Ec AroH as the only enzyme for the initial step of the shikimate pathway can grow in the absence of tryptophan. Without aromatic amino acids, this yea

SUBMITTER: Helmstaedt K 

PROVIDER: S-EPMC1175010 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature