title: Kinetics of labeling of the S-adenosylmethionine pool of Saccharomyces cerevisiae.
abstract: A method has been developed for studying the specific activity of the pool of S-adenosylmethionine in yeast. The pool reaches half-maximal specific activity within 30 s after the addition of [methyl-3H]methionine. After addition of an excess of nonradioactive methionine, the specific activity of S-adenosylmethionine is reduced by half within 20 s. During that period there is a substantial expansion of the pool. A logarithmically growing cell in synthetic medium contains about 2 X 10(6) molecules of S-adenosylmethionine, of which only 10% is used for the methylation of ribonucleic acid molecules.
mesh_terms: D000225:Adenine / Q000378:metabolism; D002250:Carbon Radioisotopes; D005656:Fungal Proteins / Q000096:biosynthesis; D007700:Kinetics; D012335:RNA, Ribosomal / Q000096:biosynthesis; D012436:S-Adenosylmethionine / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013104:Spheroplasts / Q000378:metabolism; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D005656:Fungal Proteins; D012335:RNA, Ribosomal; D014316:Tritium; D012436:S-Adenosylmethionine; D000225:Adenine