Open AccessIn vitro methylation of yeast tRNAAspby rat brain cortical tRNA-(adenine-1) methyltransferase
Author(s) -
Carlos Salas,
G. Dirheimer
Publication year - 1979
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/6.3.1123
Subject(s) - methylation , transfer rna , biology , microbiology and biotechnology , genetics , rna , gene
Rat brain cortices from young animals contain large amounts of tRNA (adenine-1)methyltransferase(s). The enzyme(s) can methylate E. coli tRNA and to a lower degree yeast tRNA. Among yeast tRNA species which can be methylated we have selected tRNAAsp as a substrate for the brain enzyme. The digestions of in vitro methylated [Me-3H]-tRNAAsp with pancreatic and/or T1 ribonucleases followed by chromatographies on DEAE-cellulose, 7 M urea, suggested that the methylation of tRNAAsp occurred at a single position within the D-loop. Further digestion of the radioactive oligonucleotide recovered after DEAE-cellulose chromatography by phosphomonoesterase and snake venom phosphodiesterase enzymes followed by bidimensional thin layer chromatography enabled us to determine the location of the adenine residue which becomes methylated by the brain enzyme. This one resulted to be the adenine 14 in the D-loop of yeast tRNAAsp.