Holger Stark and colleagues, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany, succeeded in watching the ribosom building proteins. During protein synthesis, transfer RNAs move sequentially through the A, P and E sites of the ribosome as their attached amino acids are transferred to the growing peptide chain. Large conformational movements accompany their translocation.
A staggering 1.9 million single-particle electron cryomicroscopy images were processed of the ribosome to visualize these dynamic changes.

The researchers conclude that the conformational changes are thermally driven (‘Brownian machine’). Dynamic interactions between tRNAs and ribosomal residues confine the narrow path of the tRNAs through the ribosome.

• Ribosome dynamics and tRNA movement by time-resolved electron cryomicroscopy
  Niels Fischer, Andrey L. Konevega, Wolfgang Wintermeyer, Marina V. Rodnina, Holger Stark,
  Nature 2010, 446, 329-333.
  DOI: 10.1038/nature09206
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• Watch a presentation of Ada Yonath (Nobel Prize 2009) on “The Ribosome: The Remnant of an Ancient Translation Apparatus”
• or read her Nobel Lecture in Angewandte Chemie