An enzyme from Saccharomyces cerevisiae uses NAD+ to transfer the splice junction 2'-phosphate from ligated tRNA to an acceptor molecule.
An enzyme from Saccharomyces cerevisiae which removes the splice junction 2'-phosphate from ligated tRNA appears to require NAD+. This two-component enzyme has been previously implicated in tRNA splicing because of its specificity for substrates bearing an internal 2'-phosphate and because of the absence of other observed proteins that can efficiently catalyze the same activity after fractionation of the extracts. We show here that component I of this enzyme is heat-stable, chromatographs as a small molecule, can be substituted efficiently by NAD+, and comigrates with NAD+ on a reversed-phase column. Dephosphorylation of ligated tRNA in the presence of component I or NAD+ is accompanied by stoichiometric transfer of the splice junction 2'-phosphate to an unidentified acceptor molecule.
McCraith
S M
SM
Department of Biochemistry, University of Rochester, School of Medicine and Dentistry, New York 14642.
Phizicky
E M
EM
D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D009243:NAD / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism*; D010766:Phosphorylation; D012326:RNA Splicing; D012343:RNA, Transfer / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity
D009943:Organophosphorus Compounds; D009243:NAD; D012343:RNA, Transfer