Article thumbnail

The group II intron ribonucleoprotein precursor is a large, loosely packed structure

By Tao Huang, Tanvir R. Shaikh, Kushol Gupta, Lydia M. Contreras-Martin, Robert A. Grassucci, Gregory D. Van Duyne, Joachim Frank and Marlene Belfort


Group II self-splicing introns are phylogenetically diverse retroelements that are widely held to be the ancestors of spliceosomal introns and retrotransposons that insert into DNA. Folding of group II intron RNA is often guided by an intron-encoded protein to form a catalytically active ribonucleoprotein (RNP) complex that plays a key role in the activity of the intron. To date, possible structural differences between the intron RNP in its precursor and spliced forms remain unexplored. In this work, we have trapped the native Lactococcus lactis group II intron RNP complex in its precursor form, by deleting the adenosine nucleophile that initiates splicing. Sedimentation velocity, size-exclusion chromatography and cryo-electron microscopy provide the first glimpse of the intron RNP precursor as a large, loosely packed structure. The dimensions contrast with those of compact spliced introns, implying that the RNP undergoes a dramatic conformational change to achieve the catalytically active state

Topics: RNA
Publisher: Oxford University Press
OAI identifier:
Provided by: PubMed Central

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.

Suggested articles


  1. (1997). A bacterial group II intron encoding reverse transcriptase, maturase, and DNA endonuclease activities: biochemical demonstration of maturase activity and insertion of new genetic information within the intron.
  2. (1999). A reverse-transcriptase/maturase promotes splicing by binding at its own coding segment in a group II intron RNA.
  3. (2008). A three-dimensional model of a group II intron RNA and its interaction with the intron-encoded reverse transcriptase.
  4. (1996). A variant to the ‘‘random approximation’’ of the reference-free alignment algorithm.
  5. (1996). An RNA conformational change between the two chemical steps of group II self-splicing.
  6. (2005). Calculation of standard atomic volumes for RNA and comparison with proteins: RNA is packed more tightly.
  7. (2008). Crystal structure of a self-spliced group II intron.
  8. (2003). Database for mobile group II introns.
  9. (2003). date last accessed).
  10. (2010). Disease-associated mutations that alter the RNA structural ensemble.
  11. (2005). Domain structure and three-dimensional model of a group II intron-encoded reverse transcriptase.
  12. (1994). Electrophoretic evidence that single-stranded regions of one or more nucleotides dramatically increase the flexibility of DNA.
  13. (1991). Five easy pieces.
  14. (1996). Functional analysis of promoters in the nisin gene cluster of Lactococcus lactis.
  15. (1999). Functional interactions of Prp8 with both splice sites at the spliceosomal catalytic center.
  16. (2006). Group II introns: ribozymes that splice RNA and invade DNA. The RNA World, 3rd edn.
  17. (1984). Immunoelectron microscopy of ribosomes.
  18. (1991). Intron phylogeny: a new hypothesis.
  19. (1998). Mechanical devices of the spliceosome: motors, clocks, springs, and things.
  20. (2001). Mechanism of maturase-promoted group II intron splicing.
  21. (2004). Mobile group II introns.
  22. (2002). Mobile introns: pathways and proteins.
  23. (1999). Mobile introns: retrohoming by complete reverse splicing.
  24. (1997). Multiple tertiary interactions involving domain II of group II self-splicing introns.
  25. (2010). Nuclear expression of a group II intron is consistent with spliceosomal intron ancestry.
  26. (2008). Particle-verification for single-particle, reference-based reconstruction using multivariate data analysis and classification.
  27. (2007). Preparation of macromolecular complexes for cryo-electron microscopy.
  28. (1998). Retrohoming of a bacterial group II intron: mobility via complete reverse splicing, independent of homologous DNA recombination.
  29. (1999). RNA and protein catalysis in group II intron splicing and mobility reactions using purified components.
  30. (2000). Size-distribution analysis of macromolecules by sedimentation velocity ultracentrifugation and lamm equation modeling.
  31. (2001). SmtB-DNA and protein-protein interactions in the formation of the cyanobacterial metallothionein repression complex: Zn2+ does not dissociate the protein-DNA complex in vitro.
  32. (1996). SPIDER and WEB: processing and visualization of images in 3D electron microscopy and related fields.
  33. (2008). SPIDER image processing for single-particle reconstruction of biological macromolecules from electron micrographs.
  34. (1996). Splicing of a group II intron involved in the conjugative transfer of pRS01 in lactococci.
  35. (2008). Structure and function of the Pre-mRNA splicing machine.
  36. (1986). The generality of self-splicing RNA: relationship to nuclear mRNA splicing.
  37. (2010). The tertiary structure of group II introns: Implications for biological function and evolution.
  38. (1983). The ultrastructure of macromolecular complexes studied with antibodies.
  39. (1987). Three-dimensional reconstruction from a single-exposure, random conical tilt series applied to the 50S ribosomal subunit of Escherichia coli.
  40. (1992). Three-dimensional reconstruction of single particles embedded in ice.
  41. (2004). Three-dimensional structure of a pre-catalytic human spliceosomal complex
  42. (2004). Three-dimensional structure of the native spliceosome by cryo-electron microscopy.
  43. (1997). Trans-activation of group II intron splicing by nuclear U5 snRNA.
  44. (2006). Visualization of a group II intron in the 23S rRNA of a stable ribosome.