Informational suppression as a tool for the investigation of gene structure and function

Abstract

Informational suppression, in particular nonsense suppression, has played a key role in the elucidation of the mechanism of protein biosynthesis in prokaryotes: the nature of the genetic code, structure-function relationships in tRNA and aminoacyl-tRNA synthetase reactions. Moreover, it is now possible to study protein structure and function at a highly sophisticated level through the use of a battery of different nonsense suppressors. In eukaryotes, only yeast nonsense suppressors are well characterized (although nonsense mutations have been identified in other species, including mouse). There is no doubt that these mutant tRNAs will prove as important in the investigation of eukaryotic translation machineries. Despite the fact that nonsense suppressors have not been unambiguously identified in animals cells, the availability of tyrosine-, serine- and leucine-inserting UAG, UAA and UGA yeast suppressors allows detailed analysis of both fungi and higher organisms by making use of translation systems in vitro.