Translational Control and Fidelity

Abstract

The process of protein synthesis, termed translation, is complex, involving a large molecular machine, called the ribosome, that orchestrates the interaction of a large number of trans-acting factors, both RNA and protein. A large proportion of genes are translationally regulated with most of the regulation occurring at initiation of protein synthesis. Many genes, however, are regulated at other steps in the process of translation or by co-translational regulation of mRNA stability. A special subclass of translational regulation involves regulated changes in translational fidelity. Protein synthesis proceeds at rates of up to 50 amino acids per second but while making on average fewer than one mistake in 10000 amino acids incorporated. Some mRNAs, however, increase the frequency of non-standard translation up to 50% per codon. Atomic structures of prokaryotic and eukaryotic ribosomes, first solved in 2001, provide insights into the molecular processes involved in translational control and fidelity.