Characterization of a Photosystem II core and its three-dimensional crystals.

A photosystem II core from spinach containing the chlorophyll-binding proteins 47 kDa, 43 kDa, the reaction center proteins D1, D2 and cytochromeb 559 and three low molecular weight polypeptides (MW < 10 kDa) was isolated, its three-dimensional crystals were prepared, and both core and crystals were studied by spectroscopic techniques and electron microscopy. The absorption spectra of the crystallized form of the core indicate a specific orientation of the various pigments within the crystal.