title: Composition and structure of photosystem I in the moss Physcomitrella patens.
abstract: Recently, bryophytes, which diverged from the ancestor of seed plants more than 400 million years ago, came into focus in photosynthesis research as they can provide valuable insights into the evolution of photosynthetic complexes during the adaptation to terrestrial life. This study isolated intact photosystem I (PSI) with its associated light-harvesting complex (LHCI) from the moss Physcomitrella patens and characterized its structure, polypeptide composition, and light-harvesting function using electron microscopy, mass spectrometry, biochemical, and physiological methods. It became evident that Physcomitrella possesses a strikingly high number of isoforms for the different PSI core subunits as well as LHCI proteins. It was demonstrated that all these different subunit isoforms are expressed at the protein level and are incorporated into functional PSI-LHCI complexes. Furthermore, in contrast to previous reports, it was demonstrated that Physcomitrella assembles a light-harvesting complex consisting of four light-harvesting proteins forming a higher-plant-like PSI superstructure.
authors.affiliation: VKR Research Centre Pro-Active Plants and Center for Synthetic Biology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Busch
authors.forename: Jørgen
authors.initials: J
authors.lastname: Petersen
authors.forename: Mariam T
authors.initials: MT
authors.lastname: Webber-Birungi
authors.forename: Marta
authors.initials: M
authors.lastname: Powikrowska
authors.forename: Lærke Marie Münter
authors.initials: LM
authors.lastname: Lassen
authors.forename: Bianca
authors.initials: B
authors.lastname: Naumann-Busch
authors.forename: Agnieszka Zygadlo
authors.initials: AZ
authors.lastname: Nielsen
authors.forename: Juanying
authors.initials: J
authors.lastname: Ye
authors.forename: Egbert J
authors.initials: EJ
authors.lastname: Boekema
authors.forename: Ole Nørregaard
authors.initials: ON
authors.lastname: Jensen
authors.forename: Christina
authors.initials: C
authors.lastname: Lunde
authors.forename: Poul Erik
authors.initials: PE
authors.lastname: Jensen
mesh_terms: D019068:Bryopsida / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; D020033:Protein Isoforms
keywords: Photosystem I; Physcomitrella patens; moss; photosynthesis; state transitions; structure