title: Detection of nucleoside Q precursor in methyl-deficient E.coli tRNA.
abstract: 32P-Labeled tRNAAsn was isolated from methyl-deficient E. coli tRNA. Nucleotide sequence analysis showed that tRNAAsn contains three derivatives of the Q nucleoside, possibly Q precursors, in addition to guanosine in the first position of the anticodon. One of the Q precursors was isolated on a large scale. Its UV spectra were identical with those of normal Q, indicating that 7-deazaguanosine structure having a side chain at position C-7 is complete in the Q precursor. No radioactivity was incorporated into Q or Q precursors from either [methyl-14C]methionine, [1-14C]methionine or [U-14C]methionine, showing that methionine was not directly involved in the formation of Q.
mesh_terms: D001216:Asparagine; D004926:Escherichia coli / Q000032:analysis* / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D009843:Oligoribonucleotides / Q000032:analysis; D012343:RNA, Transfer; D012263:Ribonucleosides / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009843:Oligoribonucleotides; D012263:Ribonucleosides; D001216:Asparagine; D012343:RNA, Transfer; D008715:Methionine