title: Cloning and characterization of Lonicera japonica p-coumaroyl ester 3-hydroxylase which is involved in the biosynthesis of chlorogenic acid.
abstract: Lonicera japonica is used in Chinese medicine as a source of antioxidants, primarily flavonoids, and a phenolic acid chlorogenic acid (CGA). Here we report the isolation and characterization of the full-length cDNA of LjC3H, a gene encoding p-coumaroyl ester 3-hydroxylase, an enzyme involved in CGA synthesis. Phylogenetic analysis indicated that is protein belongs to the CYP98A subfamily, and homology modeling revealed that its structure resembles that of other cytochrome P450 family proteins. Southern blot analysis indicated that more than one copy of sequences homologous to LjC3H is present in the L. japonica genome. Heterologous expression of LjC3H cDNA in Escherichia coli allowed an in vitro assay of LjC3H to be performed. This experiment revealed that the enzyme favors p-coumaroylshikimate over p-coumaroylquinate as substrate. LjC3H transcript abundance was increased both by treatment of the leaves with methyl jasmonate and by exposure to UV-B radiation. The CGA levels in the leaves of L. japonica were positively correlated with LjC3H transcript abundance.
authors.affiliation: Key Laboratory of Plant-Cell Engineering and Germ-plasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Gaobin
authors.initials: G
authors.lastname: Pu
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Bingqian
authors.initials: B
authors.lastname: Zhou
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Liu
authors.forename: Fengning
authors.initials: F
authors.lastname: Xiang
mesh_terms: D000595:Amino Acid Sequence; D002726:Chlorogenic Acid / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D031239:Lonicera / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D011487:Protein Conformation; D017385:Sequence Homology; D014466:Ultraviolet Rays
chemical_list: D018076:DNA, Complementary; D010937:Plant Growth Regulators; D002726:Chlorogenic Acid; D006899:Mixed Function Oxygenases