The ribosome: some hard facts about its structure and hot air about its evolution.

By translating genetically encoded information to synthesize proteins, the ribosome has a central and fundamental role in the molecular biology of the cell. Virtually every molecule made in every cell was made either directly by the ribosome or by enzymes made by the ribosome. Although the ribosome was discovered half a century ago, progress in the field of translation has been revolutionized by the atomic structures of the ribosomal subunits determined in 2000. These structures paved the way not only for more sophisticated biochemical and genetic experiments, but also for the phasing and/or molecular interpretation of all subsequent structures of the ribosome by crystallography or cryoEM (cryo-electron microscopy). In addition to facilitating our understanding of ribosome function, these structures also shed light on the evolution of the ribosome.