THE RPL5-RPS14-COB GENE ARRANGEMENT IN SOLANUM-TUBEROSUM - RPS14 IS ATRANSCRIBED AND UNEDITED PSEUDOGENE

The L5 ribosomal protein gene (rpl5) and a S14 ribosomal protein pseud ogene were identified by sequence analysis in the potato mitochondrial genome. The two genes are separated by one nucleotide and are found u pstream of the apocytochrome b gene (cob), an arrangement conserved al so in Arabidopsis and Brassica. The rpl5 gene has an intact open readi ng frame while the rps14 locus is disrupted by a five nucleotide dupli cation that introduces a frameshift in the reading frame. Editing of r pl5 and pseudorps14 cotranscripts has been studied by cDNA sequence an alysis. Eight C residues are edited into U in the rpl5 coding region, resulting in eight amino acid changes that increase the homology betwe en potato and other RPL5 polypeptides. Interestingly, the rps14 pseudo gene sequence is not edited at any nucleotide position.