X-ray crystallography study on ribosome recycling: the mechanism of binding and action of RRF on the 50S ribosomal subunit

EMBO J. 2005 Jan 26;24(2):251-60. doi: 10.1038/sj.emboj.7600525. Epub 2004 Dec 23.

Abstract

This study presents the crystal structure of domain I of the Escherichia coli ribosome recycling factor (RRF) bound to the Deinococcus radiodurans 50S subunit. The orientation of RRF is consistent with the position determined on a 70S-RRF complex by cryoelectron microscopy (cryo-EM). Alignment, however, requires a rotation of 7 degrees and a shift of the cryo-EM RRF by a complete turn of an alpha-helix, redefining the contacts established with ribosomal components. At 3.3 A resolution, RRF is seen to interact exclusively with ribosomal elements associated with tRNA binding and/or translocation. Furthermore, these results now provide a high-resolution structural description of the conformational changes that were suspected to occur on the 70S-RRF complex, which has implications for the synergistic action of RRF with elongation factor G (EF-G). Specifically, the tip of the universal bridge element H69 is shifted by 20 A toward h44 of the 30S subunit, suggesting that RRF primes the intersubunit bridge B2a for the action of EF-G. Collectively, our data enable a model to be proposed for the dual action of EF-G and RRF during ribosome recycling.

MeSH terms

  • Amino Acid Sequence
  • Cryoelectron Microscopy
  • Crystallography, X-Ray
  • Deinococcus / metabolism
  • Escherichia coli / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Binding
  • Protein Conformation
  • Proteins / metabolism*
  • Ribosomal Proteins
  • Ribosomes / metabolism*
  • Sequence Homology, Amino Acid

Substances

  • Proteins
  • Ribosomal Proteins
  • ribosome releasing factor

Associated data

  • PDB/1Y69