Reference "RNA editing in wheat mitochondria results in the conservation of protein sequences"

Reference ID

9082

Title

RNA editing in wheat mitochondria results in the conservation of protein sequences

Source

Nature, 1989, vol. 341, pp. 660-662

Authors (5)

Gualberto-J-M	Lamattina-L
Bonnard-G	Weil-J-H
Grienenberger-J-M

Abstract

RNA editing is a process that results in the production of a messenger RNA with
nucleotide sequences that differ from those of the template DNA, and provides
another mechanism for modulating gene expression. The phenomenon was initially
described in the mitochondria of protozoa. Here we report that RNA editing is
also required for the correct expression of plant mitochondrial genes. It has
previously been proposed that in plant mitochondria there is a departure from
the universal genetic code, with CGG specifying tryptophan instead of arginine.
This was because CGG codons are often found in plant mitochondrial genes at
positions corresponding to those encoding conserved tryptophans in other
organisms. We have now found, however, wheat mitochondrial gene sequences
containing C residues that are edited to U residues in the corresponding mRNA
sequences. In this way, CGG codons can be changed to UGG codons in the mRNA so
that tryptophan may be encoded according to the universal genetic code.
Furthermore, for each codon modification resulting from a C----U conversion that
we studied, we found a corresponding change in the amino acid that was encoded.
RNA editing in wheat mitochondria can thus maintain genetic information at the
RNA level and as a result contribute to the conservation of mitochondrial
protein sequences among plants.