The light-harvesting complex (LHC) consists of chlorophylls A and B and the chlorophyll A-B binding protein. Lhca5 is a low abundant chlorophyll a/b-binding protein that has been found to associate with Photoystem I in sub-stoechiometric amounts. Unlike the four main Lhca-types (Lhca1-4) Lhca5 seems to be able to associate with PSI or the LHCI at varying positions.