Format

Send to

Choose Destination
PLoS Biol. 2008 Sep 30;6(9):e234. doi: 10.1371/journal.pbio.0060234.

Capturing hammerhead ribozyme structures in action by modulating general base catalysis.

Author information

1
Department of Molecular and Cellular Biochemistry, Center for Structural Biology, University of Kentucky, Lexington, Kentucky, United States of America. ychi@uky.edu

Abstract

We have obtained precatalytic (enzyme-substrate complex) and postcatalytic (enzyme-product complex) crystal structures of an active full-length hammerhead RNA that cleaves in the crystal. Using the natural satellite tobacco ringspot virus hammerhead RNA sequence, the self-cleavage reaction was modulated by substituting the general base of the ribozyme, G12, with A12, a purine variant with a much lower pKa that does not significantly perturb the ribozyme's atomic structure. The active, but slowly cleaving, ribozyme thus permitted isolation of enzyme-substrate and enzyme-product complexes without modifying the nucleophile or leaving group of the cleavage reaction, nor any other aspect of the substrate. The predissociation enzyme-product complex structure reveals RNA and metal ion interactions potentially relevant to transition-state stabilization that are absent in precatalytic structures.

PMID:
18834200
PMCID:
PMC2553840
DOI:
10.1371/journal.pbio.0060234
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center