Interaction of translation initiation factor 3 with the 30S ribosomal subunit

Mol Cell. 2001 Oct;8(4):855-64. doi: 10.1016/s1097-2765(01)00356-2.


Hydroxyl radical footprinting and directed probing from Fe(II)-derivatized IF3 have been used to map the interaction of IF3 relative to 16S rRNA and tRNA(Met)(f) in the 30S ribosomal subunit. Our results place the two domains of IF3 on opposite sides of the initiator tRNA, with the C domain at the platform interface and the N domain at the E site. The C domain coincides with the location of helix 69 of 23S rRNA, explaining the ability of IF3 to block subunit association. The N domain neighbors proteins S7 and S11 and may interfere with E site tRNA binding. Our model suggests that IF3 influences initiator tRNA selection indirectly.

Publication types

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

MeSH terms

  • Binding Sites
  • Eukaryotic Initiation Factor-3
  • Hydroxyl Radical / chemistry
  • Hydroxyl Radical / metabolism*
  • Models, Molecular
  • Nucleic Acid Conformation
  • Oxidants / chemistry
  • Oxidants / metabolism
  • Peptide Initiation Factors / genetics
  • Peptide Initiation Factors / metabolism*
  • Protein Binding
  • Protein Footprinting
  • Protein Structure, Tertiary
  • RNA, Ribosomal, 16S / chemistry
  • RNA, Ribosomal, 16S / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Ribosomes / chemistry
  • Ribosomes / metabolism*


  • Eukaryotic Initiation Factor-3
  • Oxidants
  • Peptide Initiation Factors
  • RNA, Ribosomal, 16S
  • Recombinant Fusion Proteins
  • Hydroxyl Radical