Cloning And Expression Of Genes Coding For The Major Light-harvesting Chlorophyll α/b Proteins Of Photosystem Ⅱ In Green Alga Dunaliella Salina

In higher plants and algae, the reaction center of PS II is surrounded by the core antenna and the outer antenna which includes the major LHC (LHCII) and less abundant minor LHC. These light-harvesting complexes are consist of light-harvesting chlorophyll a/b proteins that bind Chl a and Chl b. LHCII proteins are the major light-harvesting chlorophyll a/b proteins of PS II which encoded by the Lhcb gene family. There are a large number of LHCII proteins with high homology. LHCII is the most abundant Chl a/b complex, alone accounts for about one-third of the total membrane protein in plant thylakoids. There are about 50% of all the chlorophylls associated with LHCII. The major function of LHCII is to absorb and transfer light energy to reaction center of PSII. Moreover, LHCII may be involved in photoprotection by dissipating excess excitation energy under high-light conditions.In higher plants, three types of LHCII proteins are encoded by Lhcb1, Lhcb2 and Lhcb3 which are highly homologous and studied well. The green algae have about the same number and complexity of chlorophyll a/b proteins as the higher plants. However, little is known about the primary structure of LhcII genes in green algae except Chlamydomonas reinhardtii which has served as a model system for studies of biochemistry and molecular cell biology.Dunaliella salina is a unicellular green alga which is unique in its ability to adapt to hypersaline environment and light stress. It is a useful model for...