Intron mutations that affect the splicing efficiency of the CYH2 gene of Saccharomyces cerevisiae.

To define the extent of intervening sequences required for efficient splicing of the CYH2 gene in Saccharomyces cerevisiae, we have constructed a series of intron mutations. Artificial intron extensions of more than 300 bp of the natural intron lead to an inhibition of splicing whereas intron deletions lead to a drastic improvement of the splicing efficiency. It is shown that deletion of a 32 bp sequence element within the intron is responsible for this drastic improvement.