2To whom correspondence should be addressed.
Submitted January 30, 1997; revision submitted March 25, 1997.
The ADE6 gene of Saccharomyces cerevisiae yeast encoding the enzyme formylglycinamidine-ribonucleotide (FGAM)-synthetase of de novo synthesis of purine nucleotides was cloned and sequenced. The gene encodes a protein consisting of 1358 amino acids. The flanking regions of 1208 (5´) and 728 bp (3´) were also sequenced. The nucleotide motif TGACTC inherent to the promotor regions of other purine genes of yeast was located (-276 bp) in the 5´-region of the gene. The amino acid sequence of the yeast FGAM-synthetase was found to contain repeats (Leu430-Ala620 and Pro810-Ile1000). Repeats of similar patterns of conserved amino acids were also detected in the structure of all other FGAM-synthetases. A homology of FGAM-synthetases with certain proteins of viruses from the Herpesviridae family was found.
KEY WORDS: Saccharomyces cerevisiae yeast, ADE6 gene, biosynthesis of purine nucleotides, formylglycinamidine-ribonucleotide synthetase, intraprotein repeat.