A U1 snRNA:pre-mRNA base pairing interaction is required early in yeast spliceosome assembly but does not uniquely define the 5' cleavage site

EMBO J. 1988 Aug;7(8):2533-8. doi: 10.1002/j.1460-2075.1988.tb03101.x.


We analyzed the effects of suppressor mutations in the U1 snRNA (SNR19) gene from Saccharomyces cerevisiae on the splicing of mutant pre-mRNA substrates. The results indicate that pairing between U1 snRNA and the highly conserved position 5 (GTATGT) of the intron occurs early in spliceosome assembly in vitro. This pairing is important for efficient splicing both in vitro and in vivo. However, pairing at position 5 does not appear to influence 5' splice site selection in vivo, indicating that the previously described U1 snRNA:5' splice junction base pairing interaction is not sufficient to define the 5' cleavage site.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Introns
  • RNA Precursors / genetics*
  • RNA Splicing*
  • RNA, Messenger / genetics*
  • RNA, Small Nuclear / genetics*
  • Saccharomyces cerevisiae / genetics*
  • Suppression, Genetic


  • RNA Precursors
  • RNA, Messenger
  • RNA, Small Nuclear