title: A single amino acid determines position specificity of an Arabidopsis thaliana CCoAOMT-like O-methyltransferase.
abstract: Caffeoyl-coenzyme A O-methyltransferase (CCoAOMT)-like proteins from plants display a conserved position specificity towards the meta-position of aromatic vicinal dihydroxy groups, consistent with the methylation pattern observed in vivo. A CCoAOMT-like enzyme identified from Arabidopsis thaliana encoded by the gene At4g26220 shows a strong preference for methylating the para position of flavanones and dihydroflavonols, whereas flavones and flavonols are methylated in the meta-position. Sequence alignments and homology modelling identified several unique amino acids compared to motifs of other CCoAOMT-like enzymes. Mutation of a single glycine, G46 towards a tyrosine was sufficient for a reversal of the unusual para- back to meta-O-methylation of flavanones and dihydroflavonols.
authors: Dept Cell and Metabolic Biology, Leibniz-Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle, Saale, Germany.
authors: Christopher Ralf
authors: CR
authors: Wils
authors: Wolfgang
authors: W
authors: Brandt
authors: Kerstin
authors: K
authors: Manke
authors: Thomas
authors: T
authors: Vogt
mesh_terms: D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000737:chemistry* / Q000201:enzymology; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000235:genetics; D044950:Flavanones / Q000737:chemistry / Q000378:metabolism; D044948:Flavonols / Q000737:chemistry / Q000378:metabolism; D005998:Glycine / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008745:Methylation; D008780:Methyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D062105:Molecular Docking Simulation; D009154:Mutation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014443:Tyrosine / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D044950:Flavanones; D044948:Flavonols; D011994:Recombinant Proteins; D014443:Tyrosine; D008780:Methyltransferases; C059825:caffeoyl-CoA O-methyltransferase; D005998:Glycine