title: Structure of CyanoP at 2.8 A: implications for the evolution and function of the PsbP subunit of photosystem II .
abstract: We present here the crystal structure of CyanoP (Tlr2075) from Thermosynechococcus elongatus at 2.8 A. CyanoP is a substoichiometric component of the isolated cyanobacterial Photosystem II (PSII) complex, distantly related to the PsbP extrinsic subunit of the oxygen-evolving PSII complex in higher plants and green algae. Despite the relatively low degree of sequence similarity, we have found that CyanoP adopts the same beta-sandwich fold as higher-plant PsbP and contains a well-conserved metal (zinc)-binding site that is also present in plant PsbP. Our results support the idea that CyanoP represents the basal structural fold of the PsbP superfamily.
authors.affiliation: Division of Biology, Wolfson Biochemistry Building, Imperial College London,South Kensington Campus, London SW7 2AZ, UK.
authors.forename: Franck
authors.initials: F
authors.lastname: Michoux
authors.forename: Kenji
authors.initials: K
authors.lastname: Takasaka
authors.forename: Marko
authors.initials: M
authors.lastname: Boehm
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Nixon
authors.forename: James W
authors.initials: JW
authors.lastname: Murray
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D000458:Cyanobacteria / Q000378:metabolism*; D019143:Evolution, Molecular; D008958:Models, Molecular; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D015032:Zinc / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D045332:Photosystem II Protein Complex; D021122:Protein Subunits; D015032:Zinc; D010100:Oxygen