Structural basis for protein synthesis: snapshots of the ribosome in motion.

The ribosome undergoes numerous large-scale conformational changes during protein synthesis, but the molecular basis for these changes have been unclear. Recent cryo-electron microscopic and X-ray crystallographic structures of both the bacterial and eukaryotic ribosome now provide snapshots of the wide range of motions that occur within the ribosome. X-ray crystallographic structures of the ribosome have also pinpointed local deformations in ribosomal RNA that occur when the two ribosomal subunits rotate with respect to each other. These structural results establish the foundation for unraveling the mechanics of the ribosome that are universal, and those that differ in bacteria and eukaryotes.