title: Trace 5-methylaminomethyl-2-selenouridine in bovine tRNA and the selenouridine synthase activity in bovine liver.
abstract: We measured the amount of Se in bovine liver tRNA. tRNA was chromatographed on a BD-cellulose column and Se-rich tRNA was eluted from the column in front of a main tRNA peak. There was 0.3 mmol Se/mol of tRNA and this level is about one tenth that of Escherichia coli tRNA. This suggests the presence of an enzyme that modifies tRNA with Se in bovine liver. We isolated the activity of this enzyme (selenouridine synthase) by chromatography of bovine liver extracts on a DEAE-cellulose column. ATP and selenophosphate synthetase, as well as selenouridine synthase and tRNA, were necessary for the reaction. 75Se was used to label the reaction products, which were analyzed by TLC after digestion with ribonuclease T2. The position of the 75Se-nucleotide on a TLC plate was identical to that of the Se-nucleotide, 5-methylaminomethyl-2-seleno-Up, prepared from 75Se-tRNA in E. coli.
authors.affiliation: Faculty of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mizutani
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Kanaya
authors.forename: Y
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: T
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D002417:Cattle / Q000235:genetics* / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D029721:Drosophila Proteins; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D008099:Liver / Q000737:chemistry* / Q000201:enzymology* / Q000648:ultrastructure; D016566:Organoselenium Compounds / Q000032:analysis*; D010770:Phosphotransferases / Q000378:metabolism; D012644:Selenium Radioisotopes; D013466:Sulfurtransferases / Q000378:metabolism*; D014529:Uridine / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D029721:Drosophila Proteins; D016566:Organoselenium Compounds; D012644:Selenium Radioisotopes; C043608:5-((methylamino)methyl)-2-selenouridine; D010770:Phosphotransferases; C062762:selenophosphate synthetase; D013466:Sulfurtransferases; C088823:tRNA 2-selenouridine synthase; D014529:Uridine