Cloning and Characterization of a Sulfonate/α-Ketoglutarate Dioxygenase from Saccharomyces cerevisiae

The Saccharomyces cerevisiae open reading frame YLL057c is predicted to encode a gene product with 31.5% amino acid sequence identity to Escherichia coli taurine/α-ketoglutarate dioxygenase and 27% identity to Ralstonia eutropha TfdA, a herbicide-degrading enzyme. Purified recombinant yeast protein is shown to be an Fe(II)-dependent sulfonate/α-ketoglutarate dioxygenase. Although taurine is a poor substrate, a variety of other sulfonates are utilized, with the best natural substrates being isethionate and taurocholate. Disruption of the gene encoding this enzyme negatively affects the use of isethionate and taurine as sulfur sources by S. cerevisiae, providing strong evidence that YLL057c plays a role in sulfonate catabolism.

酿酒酵母（Saccharomyces cerevisiae）的开放阅读框YLL057c经预测可编码一种基因产物，该产物与大肠杆菌（Escherichia coli）的牛磺酸/α-酮戊二酸双加氧酶的氨基酸序列同一性达31.5%，与真养产碱菌（Ralstonia eutropha）的除草剂降解酶TfdA的序列同一性为27%。纯化得到的重组酵母蛋白经证实为一种Fe(II)依赖型磺酸盐/α-酮戊二酸双加氧酶。尽管牛磺酸是其低效底物，但该酶可利用多种其他磺酸盐，其中最优天然底物为羟乙磺酸盐与牛磺胆酸盐。敲除该编码基因会损害酿酒酵母以羟乙磺酸盐和牛磺酸作为硫源的能力，这为YLL057c在磺酸盐分解代谢中发挥作用提供了强有力的证据。