Missel, A. ; Göringer, H. Ulrich (1994)
Trypanosoma brucei mitochondria contain RNA helicase activity.
In: Nucleic acids research, 22 (20)
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Mitochondrial gene expression in kinetoplastid organisms such as Trypanosoma, Leishmania and Crithidia requires a posttranscriptional RNA processing event known as kRNA editing. During editing, uridine nucleotides get inserted and deleted into pre-mRNAs directed by small, metabolically stable RNAs, termed guide RNAs. Although the precise mechanism of the reaction is not understood, the accepted working model describes the formation of extended anti-parallel RNA helices between gRNA molecules with pre- and partially edited mRNAs as intermediates. These duplex structures must be separated to ensure the sequential action of multiple gRNAs in a 3' to 5' polarity on the mRNA molecule. In spite of this fact, no unwinding activity has heretofore been identified in kinetoplastid mitochondria. We report the characterisation of a RNA helicase activity within Trypanosoma brucei mitochondrial extracts. The activity unwinds 25- and 48 bp, tailed RNA duplex structures but fails to separate DNA strands. It can be destroyed by heat denaturation as well as by proteinase K treatment. The activity requires magnesium cations and acts in a NTP/dNTP dependent manner. Hydrolysis of a nucleoside triphosphate is required rather than mere NTP binding as deduced from a comparison of unwinding in the presence of ATP and AMP-PCP. RNA duplexes mimicking presumed kRNA editing intermediates are substrates of the unwinding activity and therefore, we address the possible involvement of a RNA helicase activity during kRNA editing.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 1994 |
| Autor(en): | Missel, A. ; Göringer, H. Ulrich |
| Art des Eintrags: | Bibliographie |
| Titel: | Trypanosoma brucei mitochondria contain RNA helicase activity. |
| Sprache: | Englisch |
| Publikationsjahr: | 1994 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Nucleic acids research |
| Jahrgang/Volume einer Zeitschrift: | 22 |
| (Heft-)Nummer: | 20 |
| Kurzbeschreibung (Abstract): | Mitochondrial gene expression in kinetoplastid organisms such as Trypanosoma, Leishmania and Crithidia requires a posttranscriptional RNA processing event known as kRNA editing. During editing, uridine nucleotides get inserted and deleted into pre-mRNAs directed by small, metabolically stable RNAs, termed guide RNAs. Although the precise mechanism of the reaction is not understood, the accepted working model describes the formation of extended anti-parallel RNA helices between gRNA molecules with pre- and partially edited mRNAs as intermediates. These duplex structures must be separated to ensure the sequential action of multiple gRNAs in a 3' to 5' polarity on the mRNA molecule. In spite of this fact, no unwinding activity has heretofore been identified in kinetoplastid mitochondria. We report the characterisation of a RNA helicase activity within Trypanosoma brucei mitochondrial extracts. The activity unwinds 25- and 48 bp, tailed RNA duplex structures but fails to separate DNA strands. It can be destroyed by heat denaturation as well as by proteinase K treatment. The activity requires magnesium cations and acts in a NTP/dNTP dependent manner. Hydrolysis of a nucleoside triphosphate is required rather than mere NTP binding as deduced from a comparison of unwinding in the presence of ATP and AMP-PCP. RNA duplexes mimicking presumed kRNA editing intermediates are substrates of the unwinding activity and therefore, we address the possible involvement of a RNA helicase activity during kRNA editing. |
| Fachbereich(e)/-gebiet(e): | 10 Fachbereich Biologie > Genregulation und RNA-Therapeutika ?? fb10_mikrobiologie ?? 10 Fachbereich Biologie |
| Hinterlegungsdatum: | 03 Nov 2011 13:32 |
| Letzte Änderung: | 05 Mär 2013 09:55 |
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