A "CAT" family of repetitive DNA sequences in Saccharomyces cerevisiae

An oligonucleotide probe was used to isolate yeast genomic clones containing DNA sequences with repetitive elements consisting primarily of a tandemly arranged trinucleotide, CAT. Hybridization analyses estimate that the yeast genome contains 40-50 CAT clusters, representing the first repetitive DNA sequence family found in yeast. Sequence analyses show short spacers between the CAT repeats consisting of closely related trinucleotides, primarily CGT. Some of the CAT clusters are located in longer repeating elements with lengths of 7 nucleotides or more. In one case a three-times-repeated 27-nucleotide sequence bears striking homology to the 21-base pair repeat region of the mammalian simian virus 40 promoter element. Hybridization studies further suggest that the "CAT" sequences may be widely dispersed in many diverse organisms including Escherichia coli, Drosophila, and man.