Structural basis for translational stalling by human cytomegalovirus and fungal arginine attenuator peptide

Mol Cell. 2010 Oct 8;40(1):138-46. doi: 10.1016/j.molcel.2010.09.009.


Specific regulatory nascent chains establish direct interactions with the ribosomal tunnel, leading to translational stalling. Despite a wealth of biochemical data, structural insight into the mechanism of translational stalling in eukaryotes is still lacking. Here we use cryo-electron microscopy to visualize eukaryotic ribosomes stalled during the translation of two diverse regulatory peptides: the fungal arginine attenuator peptide (AAP) and the human cytomegalovirus (hCMV) gp48 upstream open reading frame 2 (uORF2). The C terminus of the AAP appears to be compacted adjacent to the peptidyl transferase center (PTC). Both nascent chains interact with ribosomal proteins L4 and L17 at tunnel constriction in a distinct fashion. Significant changes at the PTC were observed: the eukaryotic-specific loop of ribosomal protein L10e establishes direct contact with the CCA end of the peptidyl-tRNA (P-tRNA), which may be critical for silencing of the PTC during translational stalling. Our findings provide direct structural insight into two distinct eukaryotic stalling processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor / biosynthesis
  • Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor / chemistry*
  • Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor / genetics
  • Circular Dichroism
  • Cryoelectron Microscopy
  • Cytomegalovirus / genetics
  • Cytomegalovirus / metabolism*
  • Gene Expression Regulation, Fungal
  • Magnetic Resonance Spectroscopy
  • Models, Molecular
  • Nucleic Acid Conformation
  • Open Reading Frames
  • Peptide Fragments / biosynthesis
  • Peptide Fragments / chemistry*
  • Peptide Fragments / genetics
  • Peptidyl Transferases / chemistry
  • Protein Biosynthesis*
  • Protein Conformation
  • RNA, Transfer, Amino Acyl / chemistry
  • Ribosomal Proteins / chemistry
  • Ribosomes / metabolism
  • Ribosomes / ultrastructure*
  • Structure-Activity Relationship
  • Viral Envelope Proteins / biosynthesis
  • Viral Envelope Proteins / chemistry*
  • Viral Envelope Proteins / genetics
  • Yeasts / genetics
  • Yeasts / metabolism*


  • Peptide Fragments
  • RNA, Transfer, Amino Acyl
  • Ribosomal Proteins
  • UL4 protein, Human cytomegalovirus
  • Viral Envelope Proteins
  • arginine attenuator peptide
  • ribosomal protein L4
  • tRNA, peptidyl-
  • Peptidyl Transferases
  • Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor