Crystallization of the oxygen-evolving reaction centre of photosystem II in nine different detergent mixtures

Oxygen-evolving photosystem II reaction centres (RCII) isolated from both spinach and pea have been crystallized. A single crystal form grew from RCII monomers in the presence of nine different three-component mixtures of non-ionic detergents and heptane-1,2,3-triol. The crystals grew as hexagonal rods with dimensions of up to 1 × 0.3 × 0.3 mm. The crystals diffracted to a maximum resolution of 6.5 Å and belong to a hexagonal space group with unit-cell parameters a = 495, b = 495, c = 115 Å, α = β = 90, γ = 120°. The growth of a single crystal form in the presence of such a large variety of detergents suggests a very limited range of crystal lattice formation sites in the RCII complex.