title: Identification of a gene for UDP-sulfoquinovose synthase of a green alga, Chlamydomonas reinhardtii, and its phylogeny.
abstract: Sulfoquinovosyl diacylglycerol is responsible for the structural and functional integrity of the photosystem II complex of a green alga, Chlamydomonas reinhardtii. We cloned a cDNA of C. reinhardtii containing an open reading frame for a protein 36-64% identical in the primary structure to known UDP-sulfoquinovose synthases, which are required for SQDG synthesis, in other organisms. Through the introduction of the cDNA, a cyanobacterial disruptant as to the UDP-sulfoquinovose synthase gene recovered the ability to synthesize sulfoquinovosyl diacylglycerol, thus confirming that the cDNA encodes the UDP-sulfoquinovose synthase. On the genome, the cDNA was divided into 14 exons, and the gene designated as SQD1 was present as one copy. The molecular phylogenetic tree for the UDP-sulfoquinovose synthase showed grouping of C. reinhardtii together with species that require sulfoquinovosyl diacylglycerol for the functioning of the PSII complex, but not with those that do not utilize the lipid for photosynthesis. The role of sulfoquinovosyl diacylglycerol in the functioning of the photosynthetic membranes might evolve in harmony with the system of the membrane lipid synthesis such as UDP-sulfoquinovose synthase gene.
authors.affiliation: School of Life Science, Tokyo University of Pharmacy and Life Science, Horinouchi 1432-1, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sato
authors.forename: Kouichi
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Ayano
authors.initials: A
authors.lastname: Meguro
authors.forename: Mikio
authors.initials: M
authors.lastname: Tsuzuki
mesh_terms: D020418:Algal Proteins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D003001:Cloning, Molecular; D017343:Genes, Plant; D017125:Genes, Protozoan; D005964:Glucosyltransferases; D006017:Glycolipids / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D020418:Algal Proteins; D006017:Glycolipids; D045332:Photosystem II Protein Complex; C013694:sulfoquinovosyl diglyceride; D005964:Glucosyltransferases; C492484:UDP-sulfoquinovose synthase, Chlamydomonas reinhardtii