title: Evolution of the inner light-harvesting antenna protein family of cyanobacteria, algae, and plants.
abstract: Two hypotheses account for the evolution of the inner antenna light-harvesting proteins of oxygenic photosynthesis in cyanobacteria, algae, and plants: one in which the CP43 protein of photosytem II gave rise to the extrinsic CP43-like antennas of cyanobacteria (i.e. IsiA and Pcb proteins), as a late development, and the other in which CP43 and CP43-like proteins derive from an ancestral protein. In order to determine which of these hypotheses is most likely, we analyzed the family of antenna proteins by a variety of phylogenetic techniques, using alignments of the six common membrane-spanning helices, constructed using information on the antenna proteins' three-dimensional structure, and surveyed for evidence of factors that might confound inference of a correct phylogeny. The first hypothesis was strongly supported. As a consequence, we conclude that the ancestral photosynthetic apparatus, with 11 membrane-spanning helices, split at an early stage during evolution to form, on the one hand, the reaction center of photosystem II and, on the other hand, the ancestor of inner antenna proteins, CP43 (PsbC) and CP47 (PsbB). Only much later in evolution did the CP43 lineage give rise to the CP43' proteins (IsiA and Pcb) of cyanobacteria.
authors.affiliation: School of Biological Sciences, Heydon-Laurence Building A08, University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Yinan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Bing Bing
authors.initials: BB
authors.lastname: Zhou
authors.forename: Lars S
authors.initials: LS
authors.lastname: Jermiin
authors.forename: Anthony W D
authors.initials: AW
authors.lastname: Larkum
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics; D001499:Bayes Theorem; D018360:Crystallography, X-Ray; D000458:Cyanobacteria / Q000235:genetics*; D056890:Eukaryota / Q000235:genetics*; D019143:Evolution, Molecular; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000235:genetics*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D010944:Plants / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; C083100:photosystem II, chlorophyll binding protein, CP-43; C076726:chlorophyll A binding protein CP43, Cyanobacteria