A novel modified nucleoside found at the first position of the anticodon of methionine tRNA from bovine liver mitochondria

Biochemistry. 1994 Mar 1;33(8):2234-9. doi: 10.1021/bi00174a033.

Abstract

Methionine tRNA was purified from bovine liver mitochondria, and its nucleotide sequence was determined. The tRNA possesses only three posttranscriptionally modified nucleosides, two pseudouridines in the anticodon and T stems and a previously unknown nucleoside specified by the gene sequence as cytidine, in the first position of the anticodon. Structure analysis of the anticodon nucleoside by mass spectrometry revealed a molecular mass 28 Da greater than that of cytidine, and unmodified ribose, with substitution at C-5 implied by hydrogen-deuterium exchange experiments. Proton NMR of the intact tRNA showed presence of a formyl moiety, thus leading to the candidate structure 5-formylcytidine (f5C), not a previously known compound. The structure assignment was confirmed by chemical synthesis and comparison of data from combined HPLC/mass spectrometry and proton NMR for the natural and synthetic nucleosides. The potential function of f5C in the tRNA(Met) anticodon is discussed with regard to codon-anticodon interactions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Anticodon*
  • Base Sequence
  • Cattle
  • Chromatography, High Pressure Liquid / methods
  • Chromatography, Thin Layer
  • Cytidine / analogs & derivatives*
  • Cytidine / analysis
  • Cytidine / chemistry
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry / methods
  • Mitochondria, Liver / chemistry*
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Nucleosides / analysis*
  • Nucleosides / chemistry
  • RNA
  • RNA, Mitochondrial
  • RNA, Transfer, Met / chemistry*
  • RNA, Transfer, Met / isolation & purification

Substances

  • Anticodon
  • Nucleosides
  • RNA, Mitochondrial
  • RNA, Transfer, Met
  • 5-formylcytidine
  • Cytidine
  • RNA