TRINUCLEOTIDE REPEATS IN YEAST

The yeast genome exhibits a variety of trinucleotide repeat arrays wit hin protein-coding genes and intergenic regions. In the first situatio n, repeats are often not random relative to the translational frame, r esulting preferably in long stretches of the two acidic amino acids or of their corresponding amine forms. Interestingly, the longest trinuc leotide repeats are often found in genes encoding nuclearly located pr oteins. Repeats tend to be more frequent in long genes, but less frequ ent among members of gene families compared to unique genes. In the la tter case, repeat arrays often differ in length or composition between the gene homologs, indicating their instability.