Probing the interplay between the two steps of group I intron splicing: competition of exogenous guanosine with omega G.

Journal Article

One largely unexplored question about group I intron splicing is how the cleavage and ligation steps of the reaction are coordinated. We describe a simple in vitro trans-splicing model system in which both steps take place, including the exchange of ligands in the guanosine-binding site that must occur between the two steps. Using this model system, we show that the switch is accomplished by modulating the relative affinity of the binding site for the two ligands. While the terminal guanosine of the intron (omegaG) and exogenous guanosine compete for binding during the first step of splicing, no competition is apparent during the second step, when omegaG is bound tightly. These results help explain how the ribozyme orchestrates progression through the splicing reaction. In addition to providing a new tool to ask basic questions about RNA catalysis, the trans-splicing model system will also facilitate the development of therapeutically useful group I ribozymes that can repair mutant mRNAs.

Full Text

Duke Authors

Cited Authors

  • Zarrinkar, PP; Sullenger, BA

Published Date

  • December 22, 1998

Published In

Volume / Issue

  • 37 / 51

Start / End Page

  • 18056 - 18063

PubMed ID

  • 9922174

International Standard Serial Number (ISSN)

  • 0006-2960

Language

  • eng

Conference Location

  • United States