Access

You are not currently logged in.

Access JSTOR through your library or other institution:

login

Log in through your institution.

Journal Article

Capturing the Structure of a Catalytic RNA Intermediate: The Hammerhead Ribozyme

William G. Scott, James B. Murray, John R. P. Arnold, Barry L. Stoddard and Aaron Klug
Science
New Series, Vol. 274, No. 5295 (Dec. 20, 1996), pp. 2065-2069
Stable URL: http://www.jstor.org/stable/2891358
Page Count: 5

You can always find the topics here!

Topics: RNA, Crystals, Metal ions, Phosphates, Oxygen, pH, Hydrogen bonds, Crystal structure, Chemical bases, Enzymes
Were these topics helpful?
See somethings inaccurate? Let us know!

Select the topics that are inaccurate.

Cancel
  • More info
  • Add to My Lists
  • Cite this Item
Preview not available
Preview not available

Abstract

The crystal structure of an unmodified hammerhead RNA in the absence of divalent metal ions has been solved, and it was shown that this ribozyme can cleave itself in the crystal when divalent metal ions are added. This biologically active RNA fold is the same as that found previously for two modified hammerhead ribozymes. Addition of divalent cations at low pH makes it possible to capture the uncleaved RNA in metal-bound form. A conformational intermediate, having an additional Mg(II) bound to the cleavage-site phosphate, was captured by freeze-trapping the RNA at an active pH prior to cleavage. The most significant conformational changes were limited to the active site of the ribozyme, and the changed conformation requires only small additional movements to reach a proposed transition-state.

Page Thumbnails

  • Thumbnail: Page 
2065
    2065
  • Thumbnail: Page 
2066
    2066
  • Thumbnail: Page 
2067
    2067
  • Thumbnail: Page 
2068
    2068
  • Thumbnail: Page 
2069
    2069