title: Cloning and sequence analysis of the phytoene synthase gene from a unicellular chlorophyte, Dunaliella salina.
abstract: Phytoene synthase (Psy) catalyzing the dimerization of two molecules of geranylgeranyl pyrophosphate (GGPP) to phytoene may be rate limiting for the synthesis of beta-carotene in Dunaliella salina. To elucidate the carotenogenic pathway in D. salina, the complete Psy gene was first isolated by genome walking technology and suppression PCR. Subsequently, RT-PCR was performed to obtain the Psy cDNA of 1260 bp, which codes 420 amino acids. The Psy gene of total length of 2982 bp was found to consist of five exons and four introns when compared with the cDNA sequence. The D. salina Psy amino acid has a 78-89% similarity with many other higher plants, but a phylogenic analysis shows a closer relationship between the microalgal and cyanobacterial Psy.
authors.affiliation: College of Food and Biotechnology, South China University of Technology, Guangzhou 510640, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yan
authors.forename: Yue-Hui
authors.initials: YH
authors.lastname: Zhu
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Jiang
authors.forename: Dong-Lin
authors.initials: DL
authors.lastname: Song
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics*; D000460:Chlorophyta / Q000201:enzymology*; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D019207:beta Carotene / Q000096:biosynthesis
chemical_list: D019207:beta Carotene; D004247:DNA; D019883:Alkyl and Aryl Transferases; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase