Conformational Proteomics of Macromolecular Architecture: Approaching the Structure of Large Molecular Assemblies and their Mechanisms of Action

High-resolution crystal structures of functionally active ribosomal particles provide unique tools for understanding key questions concerning ribosomal function, mobility, dynamics, and involvement in cellular regulation. Structure analysis of complexes of ribosomal particles with substrate analogs and universal drugs indicated that ribosomes provide the structural frame for precise positioning of the tRNA molecules rather than participate in the catalytic event, and that the peptide bond is being formed by a nucleophilic attack of the amino moiety of the residue bound to A-site tRNA on the carbonyl carbon at the P-site. Clinically relevant antibiotics interact almost exclusively with rRNA. They interfere with substrate binding, limit the conformational mobility, block the nascent chain exit tunnel or hinder the progression of growing peptide chains.
Keywords: Protein synthesis, ribosomes, translation factors, GTP hydrolysis, L12.
In rapidly growing cells, the compounds involved in the translation of the genetic code into proteins constitute about half of the cell's dry weight and consumes up to 80% of the cell's energy. This fundamental life process involves the participation of more than a hundred components; among them is the ribosome, the largest known macromolecular enzyme.
Ribosomes are the universal cellular organelles built of two subunits of unequal size.