On the translocation of proteins across the chloroplast envelope.

Most of the chloroplast proteins are coded for in the nucleus and are synthesized in the cytosol from where they are subsequently transported into the different chloroplast compartments. The structural properties of the N-terminal extensions (transit peptides) of these nuclear-coded precursor proteins are discussed as well as the energy requirements for their translocation and the involvement of receptor proteins and that of other (ATP-dependent) factors.