title: Plant O-methyltransferases: molecular analysis, common signature and classification.
abstract: Comparative analysis of the predicted amino acid sequences of a number of plant O-methyltransferase cDNA clones show that they share some 32-71% sequence identity, and can be grouped according to the different compounds they utilise as substrates. Five highly conserved regions are proposed as a signature for plant O-methyltransferases, two of which (regions I and IV) are believed to be involved in S-adenosyl-L-methionine and metal binding, respectively. The glycine-rich signature regions include a 36 amino acid domain which is located in the mid-terminal section of the carboxy terminus of most O-methyltransferase sequences. Cladistic analysis of the amino acid sequences suggests that plant O-methyltransferases may have arisen from common ancestral genes that were driven by different structural and/or functional requirements, and whose descendants segregated into different biochemical species. A comprehensive classification of plant O-methyltransferases is proposed following the guidelines of the Commission of Plant Gene Nomenclature.
authors.affiliation: Department of Biology, Concordia University, Montréal, Québec, Canada.
authors.forename: R K
authors.initials: RK
authors.lastname: Ibrahim
authors.forename: A
authors.initials: A
authors.lastname: Bruneau
authors.forename: B
authors.initials: B
authors.lastname: Bantignies
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D018076:DNA, Complementary; D008780:Methyltransferases / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D010944:Plants / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D008780:Methyltransferases