Conversion of 5'-methylthioadenosine into S-adenosylmethionine by yeast cells.

5'-Methylthio[U-14C]adenosine was used as a culture supplement for Candida utilis. The resulting S-adenosylmethionine was hydrolyzed into its structural components. Virtually none of the label of the pentose was found in the carbohydrate part of the intracellular S-adenosylmethionine. Much of it was present in the four-carbon chain of the methionine part of the sulfonium compound. The (U-14C)-labeled adenine of 5'-methylthio[U-14C]adenosine did not contribute to the labeling of the amino acid components of the sulfonium compound.