title: Separate insertion and deletion subcomplexes of the Trypanosoma brucei RNA editing complex.
abstract: The Trypanosoma brucei editosome catalyzes the maturation of mitochondrial mRNAs through the insertion and deletion of uridylates and contains at least 16 stably associated proteins. We examined physical and functional associations among these proteins using three different approaches: purification of complexes via tagged editing ligases TbREL1 and TbREL2, comprehensive yeast two-hybrid analysis, and coimmunoprecipitation of recombinant proteins. A purified TbREL1 subcomplex catalyzed precleaved deletion editing in vitro, while a purified TbREL2 subcomplex catalyzed precleaved insertion editing in vitro. The TbREL1 subcomplex contained three to four proteins, including a putative exonuclease, and appeared to be coordinated by the zinc finger protein TbMP63. The TbREL2 subcomplex had a different composition, contained the TbMP57 terminal uridylyl transferase, and appeared to be coordinated by the TbMP81 zinc finger protein. This study provides insight into the molecular architecture of the editosome and supports the existence of separate subcomplexes for deletion and insertion editing.
authors.affiliation: Seattle Biomedical Research Institute, 4 Nickerson Street, Suite 200, Seattle, WA 98109, USA.
authors.forename: Achim
authors.initials: A
authors.lastname: Schnaufer
authors.forename: Nancy Lewis
authors.initials: NL
authors.lastname: Ernst
authors.forename: Setareh S
authors.initials: SS
authors.lastname: Palazzo
authors.forename: Jeff
authors.initials: J
authors.lastname: O'Rear
authors.forename: Reza
authors.initials: R
authors.lastname: Salavati
authors.forename: Kenneth
authors.initials: K
authors.lastname: Stuart
mesh_terms: D000818:Animals; D019729:Carbon-Oxygen Ligases / Q000737:chemistry* / Q000302:isolation & purification; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D004533:Egtazic Acid / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D017353:Gene Deletion; D005990:Glycerol / Q000737:chemistry; D008025:Ligases / Q000737:chemistry; D013058:Mass Spectrometry; D024101:Mitochondrial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D008954:Models, Biological; D009154:Mutation; D009690:Nucleic Acid Conformation; D009713:Nucleotidyltransferases / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D013347:Subcellular Fractions; D014162:Transfection; D014346:Trypanosoma brucei brucei / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D014500:Uracil Nucleotides / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014500:Uracil Nucleotides; D004533:Egtazic Acid; D012313:RNA; D009713:Nucleotidyltransferases; C034970:bacteriophage T7 induced DNA polymerase; D004259:DNA-Directed DNA Polymerase; D008025:Ligases; D019729:Carbon-Oxygen Ligases; C476580:REL1 RNA ligase, Trypanosoma brucei; C476581:REL2 RNA ligase, Trypanosoma brucei; D005990:Glycerol