title: Auxiliary functions of the PsbO, PsbP and PsbQ proteins of higher plant Photosystem II: a critical analysis.
abstract: Numerous studies over the last 25 years have established that the extrinsic PsbO, PsbP and PsbQ proteins of Photosystem II play critically important roles in maintaining optimal manganese, calcium and chloride concentrations at the active site of Photosystem II. Chemical or genetic removal of these components induces multiple and profound defects in Photosystem II function and oxygen-evolving complex stability. Recently, a number of studies have indicated possible additional roles for these proteins within the photosystem. These include putative enzymatic activities, regulation of reaction center protein turnover, modulation of thylakoid membrane architecture, the mediation of PS II assembly/stability, and effects on the reducing side of the photosystem. In this review we will critically examine the findings which support these auxiliary functions and suggest additional lines of investigations which could clarify the nature of the functional interactions of these proteins with the photosystem.
authors.affiliation: Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, LA 70803, USA. btbric@lsu.edu
authors.forename: Terry M
authors.initials: TM
authors.lastname: Bricker
authors.forename: Laurie K
authors.initials: LK
authors.lastname: Frankel
mesh_terms: D008345:Manganese / Q000737:chemistry; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism / Q000502:physiology
chemical_list: D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D021122:Protein Subunits; C054266:photosystem II manganese-stabilizing protein; D008345:Manganese