description | Protein located in or on the host thylakoid, a membranous cellular structure containing the photosynthetic pigments, reaction centers and electron-transport chain. In host chloroplast, thylakoids stack up to form the grana or stay as single cisternae and interconnect the grana Thylakoid, where photosynthesis occurs, are found in chloroplasts, cyanelles and in photosynthetic bacteria where they are the extensive invaginations of the plasma membrane |