Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

A Labile Phosphodiester Bond at the Ligation Junction in a Circular Intervening Sequence RNA

Arthur J. Zaug, Jeffrey R. Kent and Thomas R. Cech
Science
New Series, Vol. 224, No. 4649 (May 11, 1984), pp. 574-578
Stable URL: http://www.jstor.org/stable/1692906
Page Count: 5
  • More info
  • Cite this Item
A Labile Phosphodiester Bond at the Ligation Junction in a Circular Intervening Sequence RNA
Preview not available

Abstract

The excised intervening sequence of the Tetrahymena ribosomal RNA precursor mediates its own covalent cyclization in the absence of any protein. The circular molecule undergoes slow reopening at a single phosphodiester bond, the one that was formed during cyclization. The resulting linear molecular has 5$^{\prime}$-phosphate and 3$^{\prime}$-hydroxyl termini; these are unusual products for RNA hydrolysis but are typical of the other reactions mediated by this molecule. The reopened circle retains cleavage-ligation activity, as evidenced by its ability to undergo another round of cyclization and reopening. The finding that an RNA molecule can be folded so that a specific phosphate can be strained or activated helps to explain how the activation energy is lowered for RNA self-splicing. The proposed mechanisms may be relevant to several other RNA cleavage reactions that are RNA-mediated.

Page Thumbnails

  • Thumbnail: Page 
574
    574
  • Thumbnail: Page 
575
    575
  • Thumbnail: Page 
576
    576
  • Thumbnail: Page 
577
    577
  • Thumbnail: Page 
578
    578