The site of deletion of the inverted repeat in pea chloroplast DNA contains duplicated gene fragments.

Analysis of a nucleotide sequence from pea chloroplast DNA which spans the site of deletion of one copy of the large inverted repeat (IR) element suggests that the IR unit has been entirely deleted, but that the single-copy coding sequences which flanked it (trnH and ndh5) have been left intact. However, these flanking sequences have not simply been ligated together: between them there is instead a novel approximately 200 bp DNA sequence which includes two regions apparently derived by the duplication of fragments of the psbA and rbcL genes.