Translation of some chloroplast genes is checked to allow for splicing and editing

Abstract

The expression of some genes in the chloroplasts of algae and plants is regulated by the binding of nuclear-coded proteins to the mRNA. Previously, we have found and studied the candidate sites for protein binding to the 5′-untranslated regions (UTRs) of atpF, petB, clpP, psaA, psbA, and psbB genes in algal and plant chloroplasts, and traced the evolution of these sites. It was suggested that some of these sites are involved in a mechanism suppressing translation until the gene splicing is completed. These sites in the 5′-UTRs of petB, clpP, psaA, and psbA genes include a conserved helix, while those of the two remaining sites consist of several boxes devoid of this helix. This paper considers the assumption that long hairpins in the 5′-UTR near the ribosome-binding site are involved in translation suppression until the completion of editing the accD and atpH gene transcripts in the chloroplast of plant genera Adiantum and Anthoceros.