Barley (Hordeum vulgare) gene for CP29, a core chlorophyll a/b binding protein of photosystem II

The CAB super(2) protein CP29 is distinguished from LHCII proteins by its higher Chl a/b ratio (3-5 versus 1.2) and its relative abundance in the Chl b-less barley mutant, chlorina-f2, which is nearly depleted for LHCII. A genomic clone encoding CP29 was fortuitously isolated from a barley cv Bomi library by hybridization with a cDNA clone, pKG2252, encoding a LHCII type I CAB protein. Subsequently, five cDNA clones were isolated, they were all derived from the gene, and in combination the cDNA sequences covered the mRNA sequence from bp +3 to three different polyadenylation sites. The derived amino acid sequence is only about 50% homologous to LHCII type I CAB proteins and was found instead to be closely related to tomato CP29.