The chemistry of protein synthesis and voyage through the ribosomal tunnel.

High-resolution structures of ribosomal subunits and their complexes with substrates and antibiotics have revealed fundamental principles of template-directed protein synthesis. Mechanistic questions regarding ribosome function and catalysis can now be addressed with structure-based experiments. Recent studies have investigated the mechanism of peptide bond formation catalyzed by the large ribosomal subunit, the mode of protein synthesis inhibition by macrolide antibiotics, the interaction of nascent polypeptides with the ribosomal exit tunnel, and the role of ribosomal proteins in the recruitment of accessory factors that assist protein folding and targeting.