SDH1, THE GENE ENCODING THE SUCCINATE-DEHYDROGENASE FLAVOPROTEIN SUBUNIT FROM SACCHAROMYCES-CEREVISIAE

We describe the isolation, sequence and construction of a disruption of the yeast SDH1 gene, encoding the flavoprotein subunit of succinate dehydrogenase. This is the first eukaryotic flavoprotein subunit-encoding gene to be fully sequenced. The deduced amino acid (aa) sequence is 50% identical to the Escherichia coli enzyme sequence. The yeast gene encodes an N-terminal extension of 45 aa relative to the E. coli sequence which may act as a mitochondrial targeting signal. Disruption of the gene results in the inability to respire, assayed as the inability to utilize the nonfermentable carbon source, glycerol. This is the expected phenotype for disruption of an essential component of the yeast citric acid cycle.