Abstract
Organelle (plastid and mitochondria) genome encodes only 8-200 proteins, while many nuclear-encoded gene products have a signal peptide for organelle targeting. It is accepted that these genes were transferred to the nucleus from endsymbionts. The nuclear-transferred genes must acquire signal peptide sequence for organelle targeting however an overview of the acquiring process is unknown.
In this study, we search whole genome sequence of seven species for putative signal peptide sequence for organelle targeting. We defined many selected sequences as candidates of potential signal peptide sequences. A number of these candidates were fused to GFP gene, expressed in N. benthamiana., and shown to function as coding sequences for signal peptide of organelle targeting. This result suggests that genomes have capacity to incidentally give signal peptide sequence to nuclear-transferred genes.
