title: Identification and synthesis of a naturally occurring selenonucleoside in bacterial tRNAs: 5-[(methylamino)methyl]-2-selenouridine.
abstract: Escherichia coli, Clostridium sticklandii, and Methanococcus vannielii synthesize 75Se-labeled amino acid transfer ribonucleic acids [( 75Se]tRNAs) when grown with low levels (approximately equal to 1 microM) of 75SeO32-. When E. coli [75Se]tRNA was digested to nucleosides and analyzed by reversed-phase high-performance liquid chromatography, a single selenonucleoside accounted for 70-90% of the 75Se label in the bulk tRNA. This nucleoside was shown to be indistinguishable in a number of its properties from authentic 5-[(methylamino)methyl]-2-selenouridine. Preparation of the authentic selenonucleoside was accomplished and the synthetic compound characterized by its UV and 1H NMR spectral properties. The new selenonucleoside also accounted for 40-60% of the 75Se found in [75Se]tRNA from C. sticklandii or M. vannielii. Each of these anaerobic bacteria contains one additional selenonucleoside in their tRNA populations distinct from 5-[(methylamino)methyl]-2-selenouridine. Pure seleno-tRNAGlu isolated from C. sticklandii contains one 5-[(methylamino)methyl]-2-selenouridine and one 4-thiouridine per tRNA molecule.
mesh_terms: D004926:Escherichia coli / Q000032:analysis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D016566:Organoselenium Compounds; D012343:RNA, Transfer / Q000302:isolation & purification*; D011868:Radioisotopes; D012643:Selenium / Q000032:analysis* / Q000138:chemical synthesis; D013056:Spectrophotometry, Ultraviolet; D014529:Uridine / Q000031:analogs & derivatives* / Q000032:analysis / Q000138:chemical synthesis
chemical_list: D007202:Indicators and Reagents; D016566:Organoselenium Compounds; D011868:Radioisotopes; C043608:5-((methylamino)methyl)-2-selenouridine; D012343:RNA, Transfer; D012643:Selenium; D014529:Uridine