- 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. Chéret, G., Pallier, C., Valens, M., Diagnan-Fornier, B., Fukuhara, H., Bolotin-Fukuhara, M., Sor, F. Yeast (1993)