title: Native-like photosystem II superstructure at 2.44 Å resolution through detergent extraction from the protein crystal.
abstract: Photosystem II (PSII) catalyzes a key step in photosynthesis, the oxidation of water to oxygen. Excellent structural models exist for the dimeric PSII core complex of cyanobacteria, but higher order physiological assemblies readily dissociate when solubilized from the native thylakoid membrane with detergent. Here, we describe the crystallization of PSII from Thermosynechococcus elongatus with a postcrystallization treatment involving extraction of the detergent C12E8. This resulted in a transition from Type II to Type I-like membrane protein crystals and improved diffraction to 2.44 Å resolution. The obtained PSII packing in precise rows, interconnected by specific pairs of galactolipids and a loop in the PsbO subunit specific to cyanobacteria, is superimposable with previous electron microscopy images of the thylakoid membrane. The study provides a detailed model of such a superstructure and its organization of light-harvesting pigments with possible implications for the understanding of their efficient use of solar energy.
authors.affiliation: Institut für Biologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10095 Berlin, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Hellmich
authors.affiliation: Institut für Biologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10095 Berlin, Germany. Electronic address: martin.bommer@hu-berlin.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Bommer
authors.affiliation: Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Burkhardt
authors.affiliation: Institut für Biologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10095 Berlin, Germany.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ibrahim
authors.affiliation: Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Linac Coherence Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Kern
authors.affiliation: Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany.
authors.forename: Alke
authors.initials: A
authors.lastname: Meents
authors.affiliation: Institut für Theoretische Physik, Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz, Austria.
authors.forename: Frank
authors.initials: F
authors.lastname: Müh
authors.affiliation: Institut für Biologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10095 Berlin, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Dobbek
authors.affiliation: Institut für Biologie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10095 Berlin, Germany. Electronic address: athina.zouni@hu-berlin.de.
authors.forename: Athina
authors.initials: A
authors.lastname: Zouni
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000187:drug effects; D018360:Crystallography, X-Ray; D003681:Dehydration; D003902:Detergents / Q000737:chemistry*; D004987:Ethers / Q000494:pharmacology; D008958:Models, Molecular; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000187:drug effects; D011092:Polyethylene Glycols / Q000494:pharmacology; D017433:Protein Structure, Secondary; D046940:Synechococcus / Q000145:classification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D004987:Ethers; D045332:Photosystem II Protein Complex; C518220:poly(ethylene glycol) dimethyl ether; D011092:Polyethylene Glycols