Evolution from DNA to RNA recognition by the bI3 LAGLIDADG maturase

Nat Struct Mol Biol. 2005 Sep;12(9):779-87. doi: 10.1038/nsmb976. Epub 2005 Aug 21.


LAGLIDADG endonucleases bind across adjacent major grooves via a saddle-shaped surface and catalyze DNA cleavage. Some LAGLIDADG proteins, called maturases, facilitate splicing by group I introns, raising the issue of how a DNA-binding protein and an RNA have evolved to function together. In this report, crystallographic analysis shows that the global architecture of the bI3 maturase is unchanged from its DNA-binding homologs; in contrast, the endonuclease active site, dispensable for splicing facilitation, is efficiently compromised by a lysine residue replacing essential catalytic groups. Biochemical experiments show that the maturase binds a peripheral RNA domain 50 A from the splicing active site, exemplifying long-distance structural communication in a ribonucleoprotein complex. The bI3 maturase nucleic acid recognition saddle interacts at the RNA minor groove; thus, evolution from DNA to RNA function has been mediated by a switch from major to minor groove interaction.

Publication types

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

MeSH terms

  • Base Sequence
  • Binding Sites
  • Catalysis
  • Conserved Sequence
  • Crystallography, X-Ray
  • DNA / chemistry
  • DNA / metabolism*
  • Endonucleases / chemistry*
  • Endonucleases / genetics
  • Endonucleases / metabolism*
  • Evolution, Molecular*
  • Introns / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Protein Binding
  • Protein Folding
  • Protein Structure, Tertiary
  • RNA / chemistry
  • RNA / metabolism*
  • RNA Splicing
  • Structure-Activity Relationship
  • Substrate Specificity


  • RNA
  • DNA
  • Endonucleases

Associated data

  • PDB/2AB5