Crystallization of the photosynthetic light‐harvesting pigment‐protein complex B800‐850 of Rhodopseudomonas capsulata

The B800‐850 light‐harvesting complex of Rhodopseudomonas capsulata was crystallized in the presence of detergents. The crystals were obtained by a vapour diffusion technique, using polyethylene glycol as a precipitant. Crystals grew to a size of 0.5 × 0.5 × 0.3 mm within two weeks. Two different crystal forms were obtained; one is supposed to be triclinic, space group PI, the other orthorhombic, space group C2221. Both crystal forms diffract to approximately 1.0 nm. Absorption spectra and polyacrylamide gel electrophoresis demonstrate that all expected components, i.e. three polypeptides of apparent M r,8000, 10000 and 14000, bacteriochlorophyll a and carotenoids, are present and in native conformation.