Functional identification of ligands for a catalytic metal ion in group I introns.

ABSTRACT: Many enzymes use metal ions within their active sites to achieve enormous rate acceleration. Understanding how metal ions mediate catalysis requires elucidation of metal ion interactions with both the enzyme and the substrate(s). The three-dimensional arrangement determined by X-ray crystallography provides a powerful starting point for identifying ground state interactions, but only functional studies can establish and interrogate transition state interactions. The Tetrahymena group I ribozyme is a paradigm for the study of RNA catalysis, and previous work using atomic mutagenesis and quantitative analysis of metal ion rescue behavior identified catalytic metal ions making five contacts with the substrate atoms. Here, we have combined atomic mutagenesis with site-specific phosphorothioate

SUBMITTER: Forconi M 

PROVIDER: S-EPMC2758101 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature