Research Article

The Structural Basis of Ribozyme-Catalyzed RNA Assembly

See allHide authors and affiliations

Science  16 Mar 2007:
Vol. 315, Issue 5818, pp. 1549-1553
DOI: 10.1126/science.1136231

You are currently viewing the abstract.

View Full Text

Abstract

Life originated, according to the RNA World hypothesis, from self-replicating ribozymes that catalyzed ligation of RNA fragments. We have solved the 2.6 angstrom crystal structure of a ligase ribozyme that catalyzes regiospecific formation of a 5′ to 3′ phosphodiester bond between the 5′-triphosphate and the 3′-hydroxyl termini of two RNA fragments. Invariant residues form tertiary contacts that stabilize a flexible stem of the ribozyme at the ligation site, where an essential magnesium ion coordinates three phosphates. The structure of the active site permits us to suggest how transition-state stabilization and a general base may catalyze the ligation reaction required for prebiotic RNA assembly.

View Full Text