title: Identification of Lhcb gene family encoding the light-harvesting chlorophyll-a/b proteins of photosystem II in Chlamydomonas reinhardtii.
abstract: The Lhcb gene family in green plants encodes several light-harvesting Chl a/b-binding (LHC) proteins that collect and transfer light energy to the reaction centers of PSII. We comprehensively characterized the Lhcb gene family in the unicellular green alga, Chlamydomonas reinhardtii, using the expressed sequence tag (EST) databases. A total of 699 among over 15,000 ESTs related to the Lhcb genes were assigned to eight, including four new, genes that we isolated and sequenced here. A sequence comparison revealed that six of the Lhcb genes from C. reinhardtii correspond to the major LHC (LHCII) proteins from higher plants, and that the other two genes (Lhcb4 and Lhcb5) correspond to the minor LHC proteins (CP29 and CP26). No ESTs corresponding to another minor LHC protein (CP24) were found. The six LHCII proteins in C. reinhardtii cannot be assigned to any of the three types proposed for higher plants (Lhcb1-Lhcb3), but were classified as follows: Type I is encoded by LhcII-1.1, LhcII-1.2 and LhcII-1.3, and Types II, III and IV are encoded by LhcII-2, LhcII-3 and LhcII-4, respectively. These findings suggest that the ancestral LHC protein diverged into LHCII, CP29 and CP26 before, and that LHCII diverged into multiple types after the phylogenetic separation of green algae and higher plants.
authors.affiliation: Laboratory for Photo-Biology, Photodynamics Research Center, The Institute of Physical and Chemical Research (RIKEN), Sendai, 980-0845 Japan. teramoto@postman.riken.go.jp
authors.forename: H
authors.initials: H
authors.lastname: Teramoto
authors.forename: T
authors.initials: T
authors.lastname: Ono
authors.forename: J
authors.initials: J
authors.lastname: Minagawa
mesh_terms: D020418:Algal Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D061146:Chlorophyll Binding Proteins; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D020224:Expressed Sequence Tags; D045342:Light-Harvesting Protein Complexes; D018551:Solanum lycopersicum / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D017386:Sequence Homology, Amino Acid
chemical_list: D020418:Algal Proteins; C069660:CP29 light harvesting complex; D061146:Chlorophyll Binding Proteins; D018076:DNA, Complementary; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D012333:RNA, Messenger; D002734:Chlorophyll; C037184:chlorophyll b; D000077194:Chlorophyll A