Nucleotide Sequence of a Brassica napus Clp Homolog

Abstract

The chloroplast envelope plays a major role in a number of important biochemical processes including the import of plastid proteins. Most plastid proteins are synthesized as precursors and are then imported from the cytosol into the organelle via a posttranslational mechanism. The protein translocation process is believed to involve a number of factors residing in the envelope membrane. Despite the current emergence of reports conceming the characterization of the chloroplast protein import apparatus, the mechanism by which precursor proteins traverse the envelope membrane still involves a number of unidentified components (see review by Sol1 and Alefsen, 1993). The chloroplast protein import machinery clearly involves many components that need to be identified and characterized, considering the complexity of the protein translocation process, as demonstrated in the mitochondrion and the ER. One of our strategies for identifying components of the