Abstract
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.