PLANT PHYSIOLOGY , Vol 105, Issue 4 1247-1254, Copyright © 1994 by American Society of Plant Biologists
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METABOLISM AND ENZYMOLOGY |
Characterization and Partial Purification of tRNA Processing Activities from Potato Mitochondria
A. Marchfelder and A. Brennicke
Institut fur Genbiologische Forschung GmbH, Ihnestrasse 63, D-14195 Berlin, Germany
In plant mitochondria, as in most other genetic systems, several enzymatic
processing and modification steps are required to yield mature tRNAs from
primary transcripts. Three of the enzymes involved, RNase P,
3[prime]-processing activity, and tRNA nucleotidyl transferase, were
identified in potato (Solanum tuberosum) mitochondria and have been
separated by several purification steps. RNase P was partially purified,
with only a few proteins detectable in active fractions after a final
glycerol gradient step. A small RNA molecule present in fractions with
RNase P activity contains the heptanucleotide conserved in the other known
RNase P RNA sequences and may be a fragment of the RNA moiety of the plant
mitochondrial RNase P.