title: PpsR: a multifaceted regulator of photosynthesis gene expression in purple bacteria.
abstract: Purple bacteria control the level of expression and the composition of their photosystem according to light and redox conditions. This control involves several regulatory systems that have been now well characterized. Among them, the PpsR regulator plays a central role, because it directly or indirectly controls the synthesis of all of the different components of the photosystem. In this review, we report our knowledge of the PpsR protein, highlighting the diversity of its mode of action and focusing on the proteins identified in four model purple bacteria (Rhodobacter capsulatus, Rhodobacter sphaeroides, Rubrivivax gelatinosus, Bradyrhizobium ORS278). This regulator exhibits unique regulatory features in each bacterium: it can activate and/or repress the expression of photosynthesis genes, its activity can be modulated or not by the redox conditions, it can interact with other specific regulators and therefore be involved differently in light and/or redox regulatory circuits.
authors.affiliation: Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (UMR 5092 CNRS-CEA-UJF), CEA-Grenoble, 38054 Grenoble Cedex 9, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Elsen
authors.forename: Marianne
authors.initials: M
authors.lastname: Jaubert
authors.forename: David
authors.initials: D
authors.lastname: Pignol
authors.forename: Eric
authors.initials: E
authors.lastname: Giraud
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020369:Bradyrhizobium / Q000235:genetics / Q000502:physiology; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008027:Light; D010788:Photosynthesis / Q000235:genetics*; D020560:Proteobacteria / Q000235:genetics / Q000502:physiology; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016992:Rhodobacter / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D012097:Repressor Proteins