The path to RNA editing in plant mitochondria: the Halifax chapter

Abstract

A single C/T difference between gene and cDNA within the 5'-untranslated region of the wheat mtDNA-encoded cox2 (cytochrome oxidase subunit 2) sequence catalyzed the discovery of C-to-U RNA editing in plant mitochondria by a group at Dalhousie University in Halifax, Nova Scotia [Covello and Gray, (1989) Nature 341, 662-666]. Editing of codons specifying essential copper-binding ligands in the Cox2p Cu(A) site provided additional insights about the amino acid residues comprising this site, as well as illustrating the functional importance of editing in wheat mitochondria. Further investigations of RNA editing in plant mitochondria led to the subsequent discovery of a case of mitochondrion-to-nucleus gene (cox2) transfer in soybean, mediated by reverse transcription of edited cox2 mRNA.