Ribosomes, which are ?the heart of the protein biosynthesis' have been the focus of structural studies for more than 50 years. The reconstitution of some of the morphological features of the ribosome was performed many years ago. In the past few years, high-resolution structures provided molecular details of different intermediates in ribosome-mediated translation. Together, these studies have revolutionized our understanding of the mechanism of protein biosynthesis. This success depended strictly on the advances in biochemical, biophysical and genetic studies and macromolecular crystallography that have been made during last decades.