RF3 induces ribosomal conformational changes responsible for dissociation of class I release factors

Cell. 2007 Jun 1;129(5):929-41. doi: 10.1016/j.cell.2007.03.050.


During translation termination, class II release factor RF3 binds to the ribosome to promote rapid dissociation of a class I release factor (RF) in a GTP-dependent manner. We present the crystal structure of E. coli RF3*GDP, which has a three-domain architecture strikingly similar to the structure of EF-Tu*GTP. Biochemical data on RF3 mutants show that a surface region involving domains II and III is important for distinct steps in the action cycle of RF3. Furthermore, we present a cryo-electron microscopy (cryo-EM) structure of the posttermination ribosome bound with RF3 in the GTP form. Our data show that RF3*GTP binding induces large conformational changes in the ribosome, which break the interactions of the class I RF with both the decoding center and the GTPase-associated center of the ribosome, apparently leading to the release of the class I RF.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cryoelectron Microscopy
  • Crystallography, X-Ray
  • Escherichia coli / chemistry*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Guanosine Diphosphate / chemistry
  • Guanosine Diphosphate / metabolism
  • Guanosine Triphosphate / chemistry
  • Guanosine Triphosphate / metabolism
  • Molecular Structure
  • Mutation
  • Peptide Elongation Factor Tu / chemistry
  • Peptide Elongation Factor Tu / metabolism
  • Peptide Termination Factors / chemistry*
  • Peptide Termination Factors / genetics
  • Peptide Termination Factors / metabolism
  • Protein Structure, Tertiary
  • Ribosomes / chemistry*
  • Ribosomes / metabolism


  • Escherichia coli Proteins
  • Peptide Termination Factors
  • prfC protein, E coli
  • Guanosine Diphosphate
  • Guanosine Triphosphate
  • Peptide Elongation Factor Tu