DSSR-PyMOL cartoon-block schematics: PDB entry 3bwp

PDB-id

3bwp; DSSR-derived features in text and JSON formats

Class

RNA

Method

X-ray (3.1 Å)

Summary

Crystal structure of a self-spliced group ii intron

Reference

Toor N, Keating KS, Taylor SD, Pyle AM (2008): "Crystal structure of a self-spliced group II intron." Science, 320, 77-82. doi: 10.1126/science.1153803.

Abstract

Group II introns are self-splicing ribozymes that catalyze their own excision from precursor transcripts and insertion into new genetic locations. Here we report the crystal structure of an intact, self-spliced group II intron from Oceanobacillus iheyensis at 3.1 angstrom resolution. An extensive network of tertiary interactions facilitates the ordered packing of intron subdomains around a ribozyme core that includes catalytic domain V. The bulge of domain V adopts an unusual helical structure that is located adjacent to a major groove triple helix (catalytic triplex). The bulge and catalytic triplex jointly coordinate two divalent metal ions in a configuration that is consistent with a two-metal ion mechanism for catalysis. Structural and functional analogies support the hypothesis that group II introns and the spliceosome share a common ancestor.