title: Daddy, where did (PS)I come from?
abstract: The reacton centre I (RCI)-type photosystems from plants, cyano-, helio- and green sulphur bacteria are compared and the essential properties of an archetypal RCI are deduced. Species containing RCI-type photosystems most probably cluster together on a common branch of the phylogenetic tree. The predicted branching order is green sulphur, helio- and cyanobacteria. Striking similarities between RCI- and RCII-type photosystems recently became apparent in the three-dimensional structures of photosystem I (PSI), PSII and RCII. The phylogenetic relationship between all presently known photosystems is analysed suggesting (a) RCI as the ancestral photosystem and (b) the descendence of PSII from RCI via gene duplication and gene splitting. An evolutionary model trying to rationalise available data is presented.
authors.affiliation: Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Biologie Structurale et Microbiologie, Marseille, France.
authors.forename: F
authors.initials: F
authors.lastname: Baymann
authors.forename: M
authors.initials: M
authors.lastname: Brugna
authors.forename: U
authors.initials: U
authors.lastname: Mühlenhoff
authors.forename: W
authors.initials: W
authors.lastname: Nitschke
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000737:chemistry; D019414:Chlorobi / Q000737:chemistry; D000458:Cyanobacteria / Q000737:chemistry; D004734:Energy Metabolism; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000235:genetics; D045331:Photosystem I Protein Complex; D010802:Phylogeny; D017433:Protein Structure, Secondary; D016415:Sequence Alignment
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex