Abstract
The mitochondrial RNA-binding proteins (MRP) 1 and 2 play a regulatory role in RNA editing and putative role(s) in RNA processing in Trypanosoma brucei. Here, we report the purification of a high molecular weight protein complex consisting solely of the MRP1 and MRP2 proteins from the mitochondrion of T. brucei. The MRP1/MRP2 complex natively purified from T. brucei and the one reconstituted in Escherichia coli in vivo bind guide (g) RNAs and pre-mRNAs with dissociation constants in the nanomolar range, and efficiently promote annealing of pre-mRNAs with their cognate gRNAs. In addition, the MRP1/MRP2 complex stimulates annealing between two non-cognate RNA molecules suggesting that along with the cognate duplexes, spuriously mismatched RNA hybrids may be formed at some rate in vivo. A mechanism of catalysed annealing of gRNA/pre-mRNA by the MRP1/MRP2 complex is proposed.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Chromatography
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Microscopy, Electron
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Mitochondrial Proteins* / metabolism
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Mitochondrial Proteins* / physiology
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Mitochondrial Proteins* / ultrastructure
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Multidrug Resistance-Associated Proteins* / chemistry
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Multidrug Resistance-Associated Proteins* / physiology
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RNA Editing
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RNA Precursors / metabolism
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RNA Precursors / ultrastructure
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RNA, Guide, Kinetoplastida / metabolism
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RNA, Guide, Kinetoplastida / ultrastructure
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RNA, Protozoan / genetics
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RNA-Binding Proteins* / metabolism
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RNA-Binding Proteins* / ultrastructure
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Recombinant Proteins / pharmacology
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Trypanosoma brucei brucei* / genetics
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Trypanosoma brucei brucei* / metabolism
Substances
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Mitochondrial Proteins
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Multidrug Resistance-Associated Proteins
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Recombinant Proteins
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RNA Precursors
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RNA, Protozoan
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RNA-Binding Proteins
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RNA, Guide, Kinetoplastida