A trans-acting suppressor restores splicing of a yeast intron with a branch point mutation. Journal Article uri icon



  • Splicing of introns from Saccharomyces cerevisiae pre-mRNA requires the conserved sequence TACTAAC; the 3'-most A residue is utilized as the site of branch formation. We showed previously that the transcript from an actin-HIS4 gene fusion containing the mutation TACTAAC to TACTACC (designated C259) is spliced inefficiently, thereby preventing growth on the histidine precursor histidinol. By selecting for growth on histidinol, we have identified a mutant in which the splicing of the C259 transcript is increased fourfold; splicing of other mutated introns is not significantly improved. The mutant locus encodes a trans-acting suppressor. A single mutation, rna16-1, is sufficient for suppression; however, suppression is maximized in heterozygous diploids containing both rna16-1 and the wild-type allele RNA16. In addition, wild-type pre-mRNAs (and lariat intermediates) accumulate in rna16-1 cells. We propose that the RNA16 locus encodes a component of the splicing machinery.

publication date

  • July 1, 1987

has restriction

  • gold

Date in CU Experts

  • February 21, 2014 11:39 AM

Full Author List

  • Couto JR; Tamm J; Parker R; Guthrie C

author count

  • 4

Other Profiles

International Standard Serial Number (ISSN)

  • 0890-9369

Electronic International Standard Serial Number (EISSN)

  • 1549-5477

Additional Document Info

start page

  • 445

end page

  • 455


  • 1


  • 5