Characterization of two classes of ribonucleoprotein complexes possibly involved in RNA editing from Leishmania tarentolae mitochondria
Peris, M.; Frech, G.C.; Simpson, A.M.; Bringaud, F.; Byrne, E.; Bakker, A.; Simpson, L.
EMBO Journal 13(7): 1664-1672
1994
ISSN/ISBN: 0261-4189 PMID: 7512500 Document Number: 424011
The molecular mechanism of RNA editing in trypanosomatid mitochondria is an unsolved problem. We show that two classes of ribonucleoprotein complexes exist in a mitochondrial extract from Leishmania tarentolae and appear to be involved in RNA editing. The 'G' class of RNP complexes consists of 170-300 ANG particles which contain guide RNAs and proteins, show little terminal uridylyl transferase (TUTase) activity and exhibit an in vitro RNA editing-like activity. The 'T' class consists of approximately six RNP complexes, the endogenous RNA of which can be self-labeled with (alpha-32P)UTP. The most abundant T complex, T-IV, is visualized by electron microscopy as 80-140 ANG particles. This complex exhibits TUTase activity in the native gel and contains guide RNAs. Both G and T complexes are possibly involved with RNA editing in vivo. These results are a starting point for the analysis of the biochemistry of RNA editing.