title: Molecular cloning and characterization of a new cDNA encoding hyoscyamine 6beta-hydroxylase from roots of Anisodus acutangulus.
abstract: A new full-length cDNA encoding hyoscyamine 6beta-hydroxylase (designated as aah6h, GenBank Accession No. EF187826), which catalyzes the last committed step in the scopolamine biosynthetic pathway, was isolated from young roots of Anisodus acutangulus by rapid amplification of cDNA ends (RACE) for the first time. The full-length cDNA of aah6h was 1380 bp and contained a 1035 bp open reading frame (ORF) encoding a deduced protein of 344 amino acid residues. The deduced protein had an isoelectric point (pI) of 5.09 and a calculated molecular mass of about 38.7 kDa. Sequence analyses showed that AaH6H had high homology with other H6Hs isolated from some scopolamine-producing plants such as Hyoscyamus niger, Datura metel and Atropa belladonna etc. Bioinformatics analyses results indicated AaH6H belongs to 2-oxoglutarate-dependent dioxygenase superfamily. Phylogenetic tree analysis showed that AaH6H had closest relationship with H6H from A. tanguticus. Southern hybridization analysis of the genomic DNA revealed that aah6h belonged to a multi-copy gene family. Tissue expression pattern analysis firstly founded that aah6h expressed in all the tested tissues including roots, stems and leaves and indicated that aah6h was a constitutive-expression gene, which was the first reported tissue-independent h6h gene compared to other known h6h genes.
authors.affiliation: Laboratory of Plant Biotechnology, College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, People's Republic of China. gykai@shnu.edu.cn
authors.forename: Guoyin
authors.initials: G
authors.lastname: Kai
authors.forename: Junfeng
authors.initials: J
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Genyu
authors.initials: G
authors.lastname: Zhou
authors.forename: Limin
authors.initials: L
authors.lastname: Zhou
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Chen
authors.forename: Linxia
authors.initials: L
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics*; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012601:Scopolamine / Q000737:chemistry / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D019657:Solanaceae / Q000201:enzymology / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D012601:Scopolamine; D006899:Mixed Function Oxygenases; C052273:hyoscyamine (6S)-dioxygenase