title: Cloning and expression of desoxyhemigossypol-6-O-methyltransferase from cotton (Gossypium barbadense).
abstract: Terpenoids play an important role in defense against insects and pathogens in cotton. These terpenoids contain phenolic groups. Metabolites in which the phenolic group has been converted to a methoxy group are less toxic to most insects and pathogens and thus may alter resistance. Here is reported the cloning of a gene from Gossypium barbadense that encodes the enzyme that methylates the phenolic group of desoxyhemigossypol (dHG) exclusively at the 6-position, dHG-6-O-methyltransferase (dHG-6-OMT). Partial peptide sequences from digests of purified dHG-6-OMT were used to design primers for RT-PCR amplification of cDNA fragments from poly(A) mRNA. Fragments were extended to full length using 5' and 3' RACE. The resulting cDNA codes for a 365-residue polypeptide with a calculated molecular weight of 40.6 kDa, in agreement with the molecular mass of purified dHG-6-OMT. When expressed in Escherichia coli, the bacterial lysates showed a high specificity for the methylation of desoxyhemigossypol, differentiating the cloned gene from other pathogen-induced methyltransferases.
authors: Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA.
authors: Jinggao
authors: J
authors: Liu
authors: Chauncey R
authors: CR
authors: Benedict
authors: Robert D
authors: RD
authors: Stipanovic
authors: Clint W
authors: CW
authors: Magill
authors: Alois A
authors: AA
authors: Bell
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics*; D008745:Methylation; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010572:Pest Control, Biological; D010802:Phylogeny; D010935:Plant Diseases; D011994:Recombinant Proteins; D013379:Substrate Specificity; D013729:Terpenes / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; D013729:Terpenes; D008780:Methyltransferases; C459095:desoxyhemigossyol-6-O-methyltransferase