A Deletion Site Editing Endonuclease in Trypanosoma brucei
| Autor: | James Raffaello Trotter, Brian Panicucci, Nancy Lewis Ernst, Kenneth Stuart, Jason Carnes |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Ribonuclease III
Multiprotein complex Trypanosoma brucei brucei Endoribonuclease Protozoan Proteins Trypanosoma brucei Endonuclease RNA interference Endoribonucleases Animals Amino Acid Sequence RNA Messenger Molecular Biology Sequence Deletion biology RNA Cell Biology biology.organism_classification Molecular biology Mitochondria Protein Structure Tertiary Cell biology RNA editing biology.protein RNA Editing |
| Zdroj: | Molecular Cell. 20(3):403-412 |
| ISSN: | 1097-2765 |
| DOI: | 10.1016/j.molcel.2005.09.016 |
| Popis: | RNA editing in Trypanosoma brucei inserts and deletes uridines in mitochondrial mRNAs by a series of enzymatic steps that are catalyzed by a multiprotein complex, the editosome. KREPB1 and two related editosome proteins KREPB2 and KREPB3 contain motifs that suggest endonuclease and RNA/protein interaction functions. Repression of KREPB1 expression in procyclic forms by RNAi inhibited growth, in vivo editing, and in vitro endoribonucleolytic cleavage of deletion substrates. However, cleavage of insertion substrates and the exoUase, TUTase, and ligase catalytic activities of editing were retained by 20S editosomes. Repression of expression of an ectopic KREPB1 allele in bloodstream forms lacking both endogenous alleles or exclusive expression of KREPB1 with point mutations in the putative RNase III catalytic domain also blocked growth, in vivo editing, and abolished cleavage of deletion substrates, without affecting the other editing steps. These data indicate that KREPB1 is an endoribonuclease that is specific for RNA editing deletion sites. |
| Databáze: | OpenAIRE |
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