Lipidic cubic phase crystal structure of the photosynthetic reaction centre from Rhodobacter sphaeroides at 2.35A resolution.
Well-ordered crystals of the bacterial photosynthetic reaction centre from Rhodobacter sphaeroides were grown from a lipidic cubic phase. Here, we report the type I crystal packing that results from this crystallisation medium, for which 3D crystals grow as stacked 2D crystals, and the reaction centre X-ray structure is refined to 2.35A resolution. In this crystal form, the location of the membrane bilayer could be assigned with confidence. A cardiolipin-binding site is found at the protein-protein interface within the membrane-spanning region, shedding light on the formation of crystal contacts within the membrane. A chloride-binding site was identified in the membrane-spanning region, which suggests a putative site for interaction with the light-harvesting complex I, the cytochrome bc(1) complex or PufX. Comparisons with the X-ray structures of this reaction centre deriving from detergent-based crystals are drawn, indicating that a slight compression occurs in this lipid-rich environment.
Katona
Gergely
G
Department of Molecular Biotechnology, Chalmers University of Technology, P.O. Box 462, SE-405 30 Gothenburg, Sweden.
Andréasson
Ulf
U
Landau
Ehud M
EM
Andréasson
Lars-Erik
LE
Neutze
Richard
R
D001665:Binding Sites; D002308:Cardiolipins / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D003902:Detergents; D008051:Lipid Bilayers / Q000378:metabolism; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008958:Models, Molecular; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D012242:Rhodobacter sphaeroides / Q000737:chemistry*
D002308:Cardiolipins; D002712:Chlorides; D003902:Detergents; D008051:Lipid Bilayers; D008055:Lipids; D045322:Photosynthetic Reaction Center Complex Proteins