The three-dimensional structure of the ribosome and its components. 
Exciting progress has been made in the last decade by those who use physical methods to study the structure of the ribosome and its components.  The structures of 10 ribosomal proteins and three isolated ribosomal protein domains are known, and the conformations of a significant number of rRNA sequences have been determined.  Electron microscopists have made major advances in the analysis of images of ribosomes, and microscopically derived ribosome models at resolutions approaching 10A are likely quite soon.  Furthermore, ribosome crystallographers are on the verge of phasing the diffraction patterns they have had for several years, and near-atomic resolution models for entire ribosomal subunits could emerge from this source at any time.  The literature relevant to these developments is reviewed below.