Skip Navigation

This Article
Right arrow Print PDF (6909K)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (23)
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Missel, A.
Right arrow Articles by Göringer, H.U.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Missel, A.
Right arrow Articles by Göringer, H.U.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nucleic Acids Research, 1994, Vol. 22, No. 20 4050-4056
© 1994

RNA

Trypanosoma brucei mitochondria contain RNA helicase activity

Andreas Missel and H.Ulrich Göringer*

Laboratorium fur Molekulare Biologie — Genzentrum der Universitat Munchen am Max-Planck-Institut fur Biochemie Am Klopferspitz 18, 82152 Martinsried, Germany

*To whom correspondence should be addressed

Received August 1, 1994. Revised August 31, 1994. Accepted August 31, 1994.

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.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 RNAHome page
L. SIMPSON, R. APHASIZHEV, G. GAO, and X. KANG
Mitochondrial proteins and complexes in Leishmania and Trypanosoma involved in U-insertion/deletion RNA editing
RNA, February 1, 2004; 10(2): 159 - 170.
[Abstract] [Full Text] [PDF]

Home page
 Nucleic Acids ResHome page
E. A. Worthey, A. Schnaufer, I. S. Mian, K. Stuart, and R. Salavati
Comparative analysis of editosome proteins in trypanosomatids
Nucleic Acids Res., November 15, 2003; 31(22): 6392 - 6408.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
J. Koller, U. F. Muller, B. Schmid, A. Missel, V. Kruft, K. Stuart, and H. U. Goringer
Trypanosoma brucei gBP21. AN ARGININE-RICH MITOCHONDRIAL PROTEIN THAT BINDS TO GUIDE RNA WITH HIGH AFFINITY
J. Biol. Chem., February 7, 1997; 272(6): 3749 - 3757.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.