Cloning and sequencing of a gene encoding yeast thioltransferase

A 69 bp yeast genomic DNA fragment encoding yeast thioltransferase was amplified by PCR technique. A yeast genomic DNA library was screened by a specific probe obtained from the PCR product. An 718 bp DNA fragment was found to encode yeast thioltransferase and its flanking sequence. The deduced amino acid sequence of the gene, designated TTR, agrees with that derived from conventional amino acid sequence analysis except two extra amino acids on the C-terminus. In contrast to yeast thioredoxin, Southern blot analysis of total yeast genomic DNA indicated that there was only one copy of gene encoding yeast thiotransferase. A putative TATA box was found at 109 bp from the starting codon. However, no polyadenylation signal sequence was identified on the DNA sequence downstream the 3' end of the gene.