title: Tubular crystals of a photosystem II core complex.
abstract: An oxygen evolving photosystem II core complex containing all three extrinsic proteins (33, 23, 17 kDa) was isolated from spinach and reconstituted into tubular two-dimensional crystals of 72.9 nm diameter and 1-2 micrometers length. While the 17 and 23 kDa polypeptides were lost during crystallization, the extrinsic 33 kDa protein was retained. The optical spectrum of the crystallized core was characteristic of an intact PSII core complex. Immunoelectron microscopy revealed that the lumenal surface of the PSII complex was exposed at the outside of the cylindrical tubes. The projection of the complex was determined from flattened tubular crystals by negative stain electron microscopy and image analysis to 2.0 nm resolution. Rhombic unit cells (a = 16.2 nm, b = 13.7 nm; gamma = 142.4 degrees) contained one PSII complex.
authors.affiliation: M. Müller Institute for Microscopical Structure Biology, Basel, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Tsiotis
authors.forename: T
authors.initials: T
authors.lastname: Walz
authors.forename: A
authors.initials: A
authors.lastname: Spyridaki
authors.forename: A
authors.initials: A
authors.lastname: Lustig
authors.forename: A
authors.initials: A
authors.lastname: Engel
authors.forename: D
authors.initials: D
authors.lastname: Ghanotakis
mesh_terms: D003460:Crystallization; D004134:Dimyristoylphosphatidylcholine / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*; D045332:Photosystem II Protein Complex; D018724:Spinacia oleracea / Q000737:chemistry
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D004134:Dimyristoylphosphatidylcholine