Site-specific pseudouridine formation in preribosomal RNA is guided by small nucleolar RNAs

Cell. 1997 May 30;89(5):799-809. doi: 10.1016/s0092-8674(00)80263-9.


During the nucleolar maturation of eukaryotic ribosomal RNAs, many selected uridines are converted into pseudouridine by a thus far undefined mechanism. The nucleolus contains a large number of small RNAs (snoRNAs) that share two conserved sequence elements, box H and ACA. In this study, we demonstrate that site-specific pseudouridylation of rRNAs relies on short ribosomal signal sequences that are complementary to sequences in box H/ACA snoRNAs. Genetic depletion and reconstitution studies on yeast snR5 and snR36 snoRNAs demonstrate that box H/ACA snoRNAs function as guide RNAs in rRNA pseudouridylation. These results define a novel function for snoRNAs and further reinforce the idea that base pairing is the most common way to obtain specific substrate-"enzyme" interactions during rRNA maturation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Composition
  • Base Sequence
  • Molecular Sequence Data
  • RNA Precursors / genetics*
  • RNA, Small Nuclear / genetics*
  • Saccharomyces cerevisiae / genetics*
  • Uridine / genetics


  • RNA Precursors
  • RNA, Small Nuclear
  • Uridine