The goal of this proposal is to understand in molecular mechanical terms how ribosomes and the macromolecules that interact with them function to form proteins. Specifically, the proposed research is to determine how tRNAs and mRNA move in relation to each other and to ribosomal structural components during the reaction steps by which peptides are elongated on ribosomes. The appraoch is to bind fluorescently labeled tRNAs or mRNA to labeled or unlabeled ribosomes, then to measure various physical changes before and after completion of a specific reaction of the peptide elongation cycle. Probes are covalently attached at specific known sites on tRNA, mRNA analogues, ribosomal proteins and ribosomal RNA. The latter are reassembled into functionally competent ribosomes. All proteins are formed on ribosomes with mRNA and tRNA by a mechanism that appears to be similar for all organisms. Thus, knowledge of ribosome structure and function is fundamental to an understanding of how proteins, which catalyze the myriad reactions that occur in living systems, are formed at the molecular level.
