Molecular/Genetic Analysis of Transcription Termination in Yeast

The formation of a eukaryotic mRNA 3' end is a complex process involving a multitude of factors that recognize, cleave, and process the pre-mRNA, as well as those that facilitate the dissociation of RNA polymerase II (RNAP II) from the DNA template.

Although many of these factors have been identified, a comprehensive model of how the termination event interfaces with the processing activities remains elusive. In recent years, work from this laboratory has focused on a protein, Grs1p that plays an unexpected role in 3' end formation. Grs1p is the yeast Saccharomyces cerevisiae's only functional glycl tRNA synthetase. That a tRNA synthetase can function in an activity distinct from its role in translation is interesting, though not unprecedented, as tRNA synthetases have been shown to be present in the nucleus and to bind substrates other than their cognate tRNA.