Improved isolation and crystallization of Photosystem I for structural analysis

Stable trimeric Photosystem I (PS I) was isolated from the cyanobacterium Synechococcus elongatus by use of stereochemically pure beta-dodecylmaltoside. Crystals of extremely pure PS I are grown by dialysis against low salt concentration. The improved PS I crystals were the basis for a PS I model derived from X-ray structure analysis at 4 Angstrom, resolution (Krauss et al., Nat. Struct. Biol. 3 (1996) 965-973; Schubert et al., J. Mel. Biol. 272 (1997) 741-769) and for detailed information on the electron transfer chain elaborated by techniques of magnetic resonance (H. Kass, Thesis, TU-Berlin, 1995; Kamlowski et al., Biochim. Biophys. Acta 1319 (1997) 188-198 and 199-213; Bittl et al., Biochemistry 36 (1997) 12001-12004). Crystallization procedures using micro- and macroseeding are described as basis for the forthcoming structure analysis. (C) 1998 Elsevier Science B.V.