Crystal structure of the eukaryotic 40S ribosomal subunit in complex with initiation factor 1

Science. 2011 Feb 11;331(6018):730-6. doi: 10.1126/science.1198308. Epub 2010 Dec 23.


Eukaryotic ribosomes are substantially larger and more complex than their bacterial counterparts. Although their core function is conserved, bacterial and eukaryotic protein synthesis differ considerably at the level of initiation. The eukaryotic small ribosomal subunit (40S) plays a central role in this process; it binds initiation factors that facilitate scanning of messenger RNAs and initiation of protein synthesis. We have determined the crystal structure of the Tetrahymena thermophila 40S ribosomal subunit in complex with eukaryotic initiation factor 1 (eIF1) at a resolution of 3.9 angstroms. The structure reveals the fold of the entire 18S ribosomal RNA and of all ribosomal proteins of the 40S subunit, and defines the interactions with eIF1. It provides insights into the eukaryotic-specific aspects of protein synthesis, including the function of eIF1 as well as signaling and regulation mediated by the ribosomal proteins RACK1 and rpS6e.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Crystallization
  • Crystallography, X-Ray
  • Eukaryotic Initiation Factor-1 / chemistry*
  • Eukaryotic Initiation Factor-1 / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Protein Biosynthesis
  • Protein Conformation
  • Protein Folding
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / metabolism
  • RNA, Messenger / chemistry
  • RNA, Protozoan / chemistry
  • RNA, Ribosomal, 18S / chemistry*
  • Ribosomal Proteins / chemistry*
  • Ribosomal Proteins / metabolism
  • Ribosome Subunits, Small, Eukaryotic / chemistry*
  • Ribosome Subunits, Small, Eukaryotic / metabolism
  • Ribosome Subunits, Small, Eukaryotic / ultrastructure*
  • Signal Transduction
  • Tetrahymena thermophila / chemistry*
  • Tetrahymena thermophila / ultrastructure*


  • Eukaryotic Initiation Factor-1
  • Protozoan Proteins
  • RNA, Messenger
  • RNA, Protozoan
  • RNA, Ribosomal, 18S
  • Ribosomal Proteins

Associated data

  • PDB/2XZM
  • PDB/2XZN