Crystal structure of a self-spliced group II intron

Science. 2008 Apr 4;320(5872):77-82. doi: 10.1126/science.1153803.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Allosteric Regulation
  • Bacillaceae / chemistry
  • Bacillaceae / genetics*
  • Base Pairing
  • Binding Sites
  • Catalysis
  • Catalytic Domain
  • Crystallography, X-Ray
  • Evolution, Molecular
  • Introns*
  • Ligands
  • Magnesium / chemistry
  • Models, Molecular
  • Nucleic Acid Conformation
  • Phylogeny
  • RNA Splicing*
  • RNA, Bacterial / chemistry*
  • RNA, Bacterial / metabolism
  • RNA, Catalytic / chemistry*
  • RNA, Catalytic / metabolism
  • Spliceosomes / chemistry
  • Spliceosomes / metabolism


  • Ligands
  • RNA, Bacterial
  • RNA, Catalytic
  • Magnesium

Associated data

  • PDB/3BWP