Figure 5

Novel Features in the T . oceanica Chloroplast Genome. Two novel features of the T. oceanica cp genome are not found in T. pseudonana or other diatoms. The orf127 gene encodes a hypothetical transmembrane protein of 140 aa with no homology to any other proteins (a), the RNA gene flrn appears to have originated from a duplication of the conserved ffs gene that produces the RNA component of a particle involved in membrane insertion processes. An alignment of flrn to the ffs sequences from T. oceanica, T. pseudonana and P. tricornutum shows the high degree of conservation (b). EST evidence for both is weak, pointing to a potential pseudogene status, though orf127 shows a well-formed genomic structure with a strong RBS (GGGAGGG) and two stem-loops that might serve as a transcriptional terminator, while the flrn gene shows a remarkable conservation compared to its ffs counterpart with one of very few mismatches placed in the loop region (*).