Skip to main content
Article thumbnail
Location of Repository

Kinetoplastid RNA editing involves a 3′ nucleotidyl phosphatase activity

By Moritz Niemann, Heike Kaibel, Elke Schlüter, Kerstin Weitzel, Michael Brecht and H. Ulrich Göringer


Mitochondrial pre-messenger RNAs (pre-mRNAs) in African trypanosomes require RNA editing in order to mature into functional transcripts. The process involves the addition and/or removal of U nucleotides and is mediated by a high-molecular-mass complex, the editosome. Editosomes catalyze the reaction through an enzyme-driven pathway that includes endo/exoribonuclease, terminal uridylate transferase and RNA ligase activities. Here we show that editing involves an additional reaction step, a 3′ nucleotidyl phosphatase activity. The activity is associated with the editing complex and we demonstrate that the editosomal proteins TbMP99 and TbMP100 contribute to the activity. Both polypeptides contain endo-exonuclease-phosphatase domains and we show that gene ablation of either one of the two polypeptides is compensated by the other protein. However, simultaneous knockdown of both genes results in trypanosome cells with reduced 3′ nucleotidyl phosphatase and reduced editing activity. The data provide a rationale for the exoUase activity of the editosomal protein TbMP42, which generates nonligatable 3′ phosphate termini. Opposing phosphates at the two pre-mRNA cleavage fragments likely function as a roadblock to prevent premature ligation

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

Suggested articles


  1. (2003). A 100-kD complex of two RNA-binding proteins from mitochondria of Leishmania tarentolae catalyzes RNA annealing and interacts with several RNA editing components.
  2. (2005). A deletion site editing endonuclease in Trypanosoma brucei.
  3. (2003). A tale of two TUTases.
  4. (1999). A tightly regulated inducible expression system for conditional gene knock-outs and dominant-negative genetics in Trypanosoma brucei.
  5. (2005). An essential RNase III insertion editing endonuclease in Trypanosoma brucei.
  6. (2001). An RNA ligase essential for RNA editing and survival of the bloodstream form of Trypanosoma brucei.
  7. (2001). Annealing of RNA editing substrates facilitated by guide RNA-binding protein gBP21.
  8. (2001). Association of two novel proteins,
  9. (2001). Cloning and characterization of two guide RNAbinding proteins from mitochondria of Crithidia fasciculata: gBP27, a novel protein, and gBP29, the orthologue of Trypanosoma brucei gBP21.
  10. (1999). Combinatorial selection of high affinity RNA ligands to live African trypanosomes.
  11. (2003). Comparative analysis of editosome proteins in trypanosomatids.
  12. (1982). Complete analysis of cellular nucleotides by two-dimensional thin layer chromatography.
  13. (2006). Crystal structures of T. brucei MRP1/MRP2 guide-RNA binding complex reveal RNA matchmaking mechanism.
  14. (1979). Cultivation and in vitro cloning or procyclic culture forms of Trypanosoma brucei in a semi-defined medium.
  15. (1996). Direct visualization of uridylate deletion in vitro suggests a mechanism for kinetoplastid RNA editing.
  16. (1997). Disruption of a gene encoding a novel mitochondrial DEAD-box protein in Trypanosoma brucei affects edited mRNAs.
  17. (2002). Distinct functions of two RNA ligases in active Trypanosoma brucei RNA editing complexes.
  18. (2002). Editing machines: the complexities of trypanosome RNA editing.
  19. (2001). Four related proteins of the Trypanosoma brucei RNA editing complex.
  20. (1996). Guide RNA-directed uridine insertion RNA editing in vitro.
  21. (2004). High resolution crystal structure of a key editosome enzyme from Trypanosoma brucei: RNA editing ligase 1.
  22. (2001). Identification of candidate mitochondrial RNA editing ligases from Trypanosoma brucei.
  23. (2004). Identification of DNA 30-phosphatase active site residues and their differential role in DNA binding, Mg 2+ coordination, and catalysis.
  24. (2003). Identification of novel components of Trypanosoma brucei editosomes.
  25. (1975). Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of Trypanosoma brucei.
  26. (1996). In vitro import of proteins into mitochondria of Trypanosoma brucei and Leishmania tarentolae.
  27. (2000). Inhibition of Trypanosoma brucei gene expression by RNA interference using an integratable vector with opposing T7 promoters.
  28. (2001). Is CdtB a nuclease or a phosphatase?
  29. (2003). Is the Trypanosoma brucei REL1 RNA ligase specific for U-deletion RNA editing, and is the REL2 RNA ligase specific for U-insertion editing?
  30. (2001). Isolation and characterization of a U-specific 30-50-exonuclease from mitochondria of Leishmania tarentolae.
  31. (2002). Mechanism of the gBP21-mediated RNA/RNA annealing reaction: matchmaking and charge reduction.
  32. (2004). Mitochondrial proteins and complexes in Leishmania and Trypanosoma involved in U-insertion/deletion RNA editing.
  33. (2002). Purification and partial characterization of a DNA 30-phosphatase from Schizosaccharomyces pombe.
  34. (1997). Purification of a functional enzymatic editing complex from Trypanosoma brucei mitochondria.
  35. (2005). Reconstitution of uridine-deletion precleaved RNA editing with two recombinant enzymes.
  36. (1997). Resolution of the RNA editing gRNA-directed endonuclease from two other endonucleases of Trypanosoma brucei mitochondria.
  37. (1998). Ribonuclease A.
  38. (1982). Ribonuclease T1.
  39. (2002). Ribonucleases from T2 family.
  40. (2008). RNA editing in Trypanosoma brucei requires three different editosomes.
  41. (1996). RNA editing: a mechanism for gRNA-specified uridylate insertion into precursor mRNA.
  42. (1994). RNA editing: transfer of genetic information from gRNA to precursor mRNA in vitro.
  43. (1995). RNA ligase and its involvement in guide RNA/mRNA chimera formation. Evidence for a cleavageligation mechanism of Trypanosoma brucei mRNA editing.
  44. (2002). RNase P RNA-mediated catalysis.
  45. (2002). Role of uridylate-specific exoribonuclease activity in Trypanosoma brucei RNA editing.
  46. (2003). Separate insertion and deletion subcomplexes of the Trypanosoma brucei RNA editing complex.
  47. (1987). Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
  48. (2000). T-Coffee: a novel method for fast and accurate multiple sequence alignment.
  49. (2006). Taking U out, with two nucleases?
  50. (2008). TbMP42 is a structure-sensitive ribonuclease that likely follows a metal ion catalysis mechanism.
  51. (2005). TbMP42, a protein component of the RNA editing complex in African trypanosomes, has endo-exoribonuclease activity.
  52. (2003). TbMP57 is a 30 terminal uridylyl transferase (TUTase) of the Trypanosoma brucei editosome.
  53. (1994). The formation of mitochondrial ribonucleoprotein complexes involving guide RNA molecules in Trypanosoma brucei.
  54. (2008). The function of RNA editing in Trypanosomes.
  55. (2008). The KREPA3 zinc finger motifs and OB-fold domain are essential for RNA editing and survival of Trypanosoma brucei.
  56. (2006). The SWISS-MODEL Repository: new features and functionalities.
  57. (2001). The two RNA ligases of the Trypanosoma brucei RNA editing complex: cloning the essential band IV gene and identifying the band V gene.
  58. (1998). tRNA splicing.
  59. (1994). Trypanosoma brucei mitochondria contain RNA helicase activity.
  60. (2008). Trypanosoma brucei RNA editing protein TbMP42 (band VI) is crucial for Nucleic Acids Research,2009,
  61. (1996). Trypanosome U-deletional RNA editing involves guide RNA-directed endonuclease cleavage, terminal U exonuclease, and RNA ligase activities.
  62. (1998). Unexpected electrophoretic migration of RNA with different 30 termini causes a RNA sizing ambiguity that can be resolved using nuclease P1-generated sequencing ladders.
  63. (2007). Uridylate-specific 30 50-exoribonucleases involved in uridylate-deletion RNA editing in trypanosomatid mitochondria.
  64. (2008). Working together: the RNA editing machinery in Trypanosoma brucei.I nG o ¨

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