Structure and function of the native and recombinant mitochondrial MRP1/MRP2 complex from Trypanosoma brucei.
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.
Zíková
Alena
A
Institute of Parasitology, Czech Academy of Sciences, Ceské Budejovice, Czech Republic.
Kopecná
Jana
J
Schumacher
Maria A
MA
Stuart
Kenneth
K
Trantírek
Lukás
L
Lukes
Julius
J
D002845:Chromatography; D008854:Microscopy, Electron; D024101:Mitochondrial Proteins / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000737:chemistry / Q000502:physiology; D011994:Recombinant Proteins / Q000494:pharmacology; D017393:RNA Editing; D012322:RNA Precursors / Q000378:metabolism / Q000648:ultrastructure; D017394:RNA, Guide, Kinetoplastida / Q000378:metabolism / Q000648:ultrastructure; D016053:RNA, Protozoan / Q000235:genetics; D016601:RNA-Binding Proteins / Q000378:metabolism / Q000648:ultrastructure; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000378:metabolism
D024101:Mitochondrial Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011994:Recombinant Proteins; D012322:RNA Precursors; D017394:RNA, Guide, Kinetoplastida; D016053:RNA, Protozoan; D016601:RNA-Binding Proteins