title: Native mRNA editing complexes from Trypanosoma brucei mitochondria.
abstract: The aim of this study was to identify multicomponent complexes involved in kinetoplastid mitochondrial mRNA editing. Mitochondrial extracts from Trypanosoma brucei were fractionated on 10-30% glycerol gradients and assayed for RNAs and activities potentially involved in editing, including pre-edited mRNA, guide RNA (gRNA), endonuclease, terminal uridylyltransferase (TUTase), RNA ligase and gRNA-mRNA chimera-forming activities. These experiments suggest that two distinct editing complexes exist. Complex I (19S) consists of gRNA, TUTase, RNA ligase and chimera-forming activity. Complex II (35-40S) is composed of gRNA, preedited mRNA, RNA ligase and chimera-forming activity. These studies provide the first evidence that editing occurs in a multicomponent complex. The possible roles of complex I, complex II and RNA ligase in editing are discussed.
authors.affiliation: Department of Biochemistry, University of Alabama, School of Medicine, Birmingham 35294.
authors.forename: V W
authors.initials: VW
authors.lastname: Pollard
authors.forename: M E
authors.initials: ME
authors.lastname: Harris
authors.forename: S L
authors.initials: SL
authors.lastname: Hajduk
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D004277:DNA, Single-Stranded; D004720:Endonucleases / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D017393:RNA Editing; D011130:RNA Ligase (ATP) / Q000378:metabolism; D012316:RNA Nucleotidyltransferases / Q000378:metabolism; D017394:RNA, Guide, Kinetoplastida / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D016053:RNA, Protozoan / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000378:metabolism*
chemical_list: D004277:DNA, Single-Stranded; D012333:RNA, Messenger; D016053:RNA, Protozoan; D012316:RNA Nucleotidyltransferases; C031687:UTP-RNA uridylyltransferase; D004720:Endonucleases; D011130:RNA Ligase (ATP); D017394:RNA, Guide, Kinetoplastida