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  • The EMBO Journal (2003) 22, 913 - 924
  • doi:10.1093/emboj/cdg083

Isolation of a U-insertion/deletion editing complex from Leishmania tarentolae mitochondria

Ruslan Aphasizhev1, Inna Aphasizheva2, Robert E. Nelson1, Guanghan Gao2, Agda M. Simpson1, Xuedong Kang2, Arnold M. Falick3, Sandro Sbicego2 and Larry Simpson1,2

  1. Department of Microbiology, Immunology and Molecular Genetics, 6780 MacDonald Research Laboratories, Los Angeles, CA 90095, USA
  2. Howard Hughes Medical Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA
  3. Howard Hughes Medical Institute Mass Spectrometry Laboratory, Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA

Correspondence to:

Larry Simpson, E-mail: simpson@kdna.ucla.edu

Received 6 November 2002; Accepted 19 December 2002; Revised 5 December 2002

A multiprotein, high molecular weight complex active in both U-insertion and U-deletion as judged by a pre-cleaved RNA editing assay was isolated from mitochondrial extracts of Leishmania tarentolae by the tandem affinity purification (TAP) procedure, using three different TAP-tagged proteins of the complex. This editing- or E-complex consists of at least three protein-containing components interacting via RNA: the RNA ligase-containing L-complex, a 3' TUTase (terminal uridylyltransferase) and two RNA-binding proteins, Ltp26 and Ltp28. Thirteen approximately stoichiometric components were identified by mass spectrometric analysis of the core L-complex: two RNA ligases; homologs of the four Trypanosoma brucei editing proteins; and seven novel polypeptides, among which were two with RNase III, one with an AP endo/exonuclease and one with nucleotidyltransferase motifs. Three proteins have no similarities beyond kinetoplastids.

  • Keywords:

    • editosome,
    • RNA editing,
    • TAP,
    • TUTase