Cloning of the RNA2 gene of Saccharomyces cerevisiae.

The RNA2 gene of Saccharomyces cerevisiae, which has been implicated in splicing the transcripts of nuclear protein coding genes, has been cloned by complementation of the temperature-sensitive growth defect of an rna2-1 mutant strain. The cloned sequence also suppresses the accumulation of unspliced precursor transcripts of the actin gene in an rna2-1 mutant. The gene has been localised to a 3.2-kb DNA restriction fragment and the corresponding low abundance 2.8-kb transcript identified and the 5' ends mapped. Evidence that this cloned sequence represents the RNA2 gene includes homologous integration at the rna2-1 locus and disruption of the RNA2 gene by insertional inactivation. The disrupted allele confers a recessive lethal phenotype, indicating an essential function for the RNA2 gene product.