Enzymatic synthesis of Q nucleoside containing mannose in the anticodon of tRNA: isolation of a novel mannosyltransferase from a cell-free extract of rat liver.
The Q nucleosides isolated from rabbit liver tRNA are known to have sugars (mannose or galactose) linked to their cyclopentene diol moiety. A Q nucleoside containing mannose (manQ) was synthesized by a cell-free system from rat liver, using purified E. coli tRNAAsp as an acceptor and GDP-mannose as a donor molecule. The novel mannosyltransferase catalyzing this reaction was purified from a particulate-free soluble enzyme fraction and found to be strictly specific for tRNAAsp. These results, together with the anomeric configuration of mannose in Q nucleoside, indicate that no lipid intermediate is involved in the biosynthesis of Q nucleoside.
D000818:Animals; D000926:Anticodon; D004492:Edetic Acid / Q000494:pharmacology; D006602:Hexosyltransferases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008364:Mannosyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D012343:RNA, Transfer / Q000096:biosynthesis; D051381:Rats; D012263:Ribonucleosides / Q000096:biosynthesis*; D012965:Sodium Chloride / Q000494:pharmacology
D000926:Anticodon; D012263:Ribonucleosides; D012965:Sodium Chloride; D012343:RNA, Transfer; D004492:Edetic Acid; D006602:Hexosyltransferases; D008364:Mannosyltransferases; D008274:Magnesium