1H and 15N resonance assignments and structure of the N-terminal domain of Escherichia coli initiation factor 3

Eur J Biochem. 1995 Mar 1;228(2):395-402.


Initiation factor IF3 from Escherichia coli is composed of two domains connected by a hydrophilic peptide. In this study, the N-terminal domain (residues 7-83) has been overexpressed, 15N labelled and purified. NMR assignments for this domain have been obtained by two-dimensional and three-dimensional heteronuclear and homonuclear spectroscopy. Using distance geometry and simulated annealing, a three-dimensional solution structure was calculated using 506 NOE and 56 dihedral angle restraints. The resulting structure is composed of a five-stranded antiparallel beta sheet surrounded by two alpha helices. Since the heteronuclear 1H-15N correlation spectrum of the N-terminal domain of IF3 is an almost exact subset of that of the native protein, the assignments obtained and the structure calculated should be directly transposable to the full-length protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Escherichia coli / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Peptide Initiation Factors / chemistry*
  • Prokaryotic Initiation Factor-3
  • Protein Conformation
  • Protein Structure, Secondary


  • Peptide Initiation Factors
  • Prokaryotic Initiation Factor-3