The light-harvesting complex (LHC) functions as a light receptor, it captures and delivers excitation energy to photosystems with which it is closely associated. May channel protons produced in the catalytic Mn center of water oxidation into the thylakoid lumen. Binds at least 14 chlorophylls (8 Chl-a and 6 Chl-b) and carotenoids such as lutein and neoxanthin. The LHC complex consists of chlorophyll a-b binding proteins. Down-regulated by UV-B. The N-terminus of the protein extends into the stroma where it is involved with adhesion of granal membranes and post-translational modifications; both are believed to mediate the distribution of excitation energy between photosystems I and II. Photoregulated by reversible phosphorylation of its threonine residues. Belongs to the light-harvesting chlorophyll a/b-binding (LHC) protein family.