title: Molecular cloning and characterization of the gene encoding squalene epoxidase in Panax notoginseng.
abstract: Squalene epoxidase (SE) is one of the rate-limiting enzymes in the triterpene saponins biosynthetic pathway. Panax notoginseng, one of the famous medicinal plants in China, produces bioactive triterpene saponins. Here we report the P. notoginseng SE, which was cloned from the root of P. notoginseng by PCR. The nucleotide sequence of the ORF (GenBank accession no. DQ386734) contains 1611 nucleotides and encodes 537 amino acid residues with molecular weight of 59.14 kDa and pI of 8.81. The gene has 98% identity with P. ginseng but different identities with other SE families. P. notoginseng SE has a FAD function domain, NAD(P)-binding Rossmann-fold domains, hydrophobicity and 4 transmembrane helices. This SE may be a microsomal membrane-associated enzyme. Real time quantitative PCR shows that the cDNA has different expression pattern and is highly expressed in root, especially in 3-year-old root.
authors.affiliation: Sichuan Key Laboratory of Molecular Biology and Biotechnology, College of Life Science, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Fengmei
authors.initials: F
authors.lastname: He
authors.forename: Yongping
authors.initials: Y
authors.lastname: Zhu
authors.forename: Mingxiong
authors.initials: M
authors.lastname: He
authors.forename: Yizheng
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D053723:Panax notoginseng / Q000201:enzymology* / Q000235:genetics*; D010802:Phylogeny; D050603:Squalene Monooxygenase / Q000737:chemistry / Q000235:genetics*
chemical_list: D050603:Squalene Monooxygenase