tRNA recognition by glutamyl-tRNA reductase

J Biol Chem. 2004 Aug 13;279(33):34931-7. doi: 10.1074/jbc.M401529200. Epub 2004 Jun 11.

Abstract

During the first step of porphyrin biosynthesis in Archaea, most bacteria, and in chloroplasts glutamyl-tRNA reductase (GluTR) catalyzes the NADPH-dependent reduction of glutamyl-tRNA to glutamate-1-semialdehyde. Elements in tRNA(Glu) important for utilization by Escherichia coli GluTR were determined by kinetic analysis of 51 variant transcripts of E. coli Glu-tRNA(Glu). Base U8, the U13*G22**A46 base triple, the tertiary Watson-Crick base pair 19*56, and the lack of residue 47 are required for GluTR recognition. All of these bases contribute to the formation of the unique tertiary core of E. coli tRNA-(Glu). Two tRNA(Glu) molecules lacking the entire anticodon stem/loop but retaining the tertiary core structure remained substrates for GluTR, while further decreasing tRNA size toward a minihelix abolished GluTR activity. RNA footprinting experiments revealed the physical interaction of GluTR with the tertiary core of Glu-tRNA(Glu). E. coli GluTR showed clear selectivity against mischarged Glu-tRNA(Gln). We concluded that the unique tertiary core structure of E. coli tRNA(Glu) was sufficient for E. coli GluTR to distinguish specifically its glutamyl-tRNA substrate.

Publication types

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

MeSH terms

  • Aldehyde Oxidoreductases / metabolism*
  • Chromatography, High Pressure Liquid
  • Circular Dichroism
  • Escherichia coli / metabolism
  • Genetic Variation
  • Genetic Vectors
  • Kinetics
  • Nucleic Acid Conformation
  • Protein Conformation
  • RNA, Messenger / metabolism
  • RNA, Transfer / metabolism*
  • RNA, Transfer, Glu / metabolism
  • Recombinant Proteins / metabolism
  • Spectrophotometry
  • Temperature
  • Ultraviolet Rays

Substances

  • RNA, Messenger
  • RNA, Transfer, Glu
  • Recombinant Proteins
  • RNA, Transfer
  • Aldehyde Oxidoreductases
  • glutamyl tRNA reductase