Functional and mutational analysis of the light-harvesting chlorophyll a/b protein of thylakoid membranes.

Abstract. The precursor for a Lemna light-harvesting chlorophyll a/b protein (pLHCP) has been synthesized in vitro from a single member of the nuclear LHCP multigene family. We report the sequence of this gene. When incubated with Lemna chloroplasts, the pLHCP is imported and processed into several polypeptides, and the mature form is assembled into the light-harvesting complex of photosystem II (LHC II). The accumulation of the processed LHCP is enhanced by the addition to the chloroplasts of a precursor and a co-factor for chlorophyll biosynthesis. Using a model for the arrangement of the mature polypeptide in the thylakoid membrane as a guide, we have created mutations that lie within the mature coding I N higher plants light-harvesting complexes (LHCs) l located in the chloroplast thylakoid membrane transfer absorbed light energy to photochemical reaction centers (l 9, 46). The major protein component of the LHC of photosystem II (LHC II) of green plants is encoded by a nuclea