The DNA sequence analysis of the HAP4-LAP4 region on chromosome XI of Saccharomyces cerevisiae suggests the presence of a second aspartate aminotransferase gene in yeast.

The nucleotide sequence of a 19,000 base pair region from the left arm of chromosome XI of Saccharomyces cerevisiae has been determined and analysed. It covers the HAP4-GFA1-LAP4 loci already described. As expected HAP4, GFA1 and LAP4 genes have been found and six new open reading frames (ORFs) with a coding capacity of more than 100 amino acid residues have been identified.