Structure of the ribosome post-recycling complex probed by chemical cross-linking and mass spectrometry

Nat Commun. 2016 Nov 8:7:13248. doi: 10.1038/ncomms13248.

Abstract

Ribosome recycling orchestrated by the ATP binding cassette (ABC) protein ABCE1 can be considered as the final-or the first-step within the cyclic process of protein synthesis, connecting translation termination and mRNA surveillance with re-initiation. An ATP-dependent tweezer-like motion of the nucleotide-binding domains in ABCE1 transfers mechanical energy to the ribosome and tears the ribosome subunits apart. The post-recycling complex (PRC) then re-initiates mRNA translation. Here, we probed the so far unknown architecture of the 1-MDa PRC (40S/30S·ABCE1) by chemical cross-linking and mass spectrometry (XL-MS). Our study reveals ABCE1 bound to the translational factor-binding (GTPase) site with multiple cross-link contacts of the helix-loop-helix motif to the S24e ribosomal protein. Cross-linking of the FeS cluster domain to the ribosomal protein S12 substantiates an extreme lever-arm movement of the FeS cluster domain during ribosome recycling. We were thus able to reconstitute and structurally analyse a key complex in the translational cycle, resembling the link between translation initiation and ribosome recycling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaeal Proteins / metabolism
  • Cross-Linking Reagents / chemistry*
  • Iron-Sulfur Proteins / metabolism
  • Mass Spectrometry / methods*
  • Models, Molecular
  • Ribosomal Proteins / metabolism
  • Ribosomes / chemistry*
  • Ribosomes / metabolism*
  • Ribosomes / ultrastructure
  • Sulfolobus solfataricus / metabolism

Substances

  • Archaeal Proteins
  • Cross-Linking Reagents
  • Iron-Sulfur Proteins
  • Ribosomal Proteins