Cloning and sequencing of sulfite reductase alpha subunit gene from Saccharomyces cerevisiae

A DNA fragment of 2.1 kb was specifically amplified by PCR with primers based on the amino acid sequences obtained from the N-terminal region and the cyanogen bromide-derived peptide of the sulfite reductase alpha subunit in Saccharomyces cerevisiae. With this fragment as a probe, the gene coding for the sulfite reductase alpha subunit was isolated from a genomic library of S. cerevisiae. Sequencing analysis revealed that the gene contains a 3105-bp open reading frame, which is large enough to code for a protein of 1035 amino acid residues. The transcript of the sulfite reductase alpha subunit gene was detected by Northern analysis after methionine deprivation, but the amount of the transcript did not directly correlate with the enzyme activity. The DNA fragment containing the sulfite reductase alpha subunit gene rescued the met10 phenotype by complementation.