Conserved sequence motifs in plant S-adenosyl-L-methionine-dependent methyltransferases.
Plant S-adenosyl-L-methionine-dependent methyltransferases (SAM-Mtases) are the key enzymes in phenylpropanoid, flavonoid and many other metabolic pathways of biotechnological importance. Here we compiled the amino acid sequences of 56 SAM-Mtases from different plants and performed a computer analysis for the conserved sequence motifs that could possibly act as SAM-binding domains. To date, genes or cDNAs encoding at least ten distinct groups of SAM-Mtases that utilize SAM and a variety of substrates have been reported from higher plants. Three amino acid sequence motifs are conserved in most of these SAM-Mtases. In addition, many conserved domains have been discovered in each group of O-methyltransferases (OMTs) that methylate specific substrates and may act as sites for substrate specificity in each enzyme. Finally, a diagrammatic representation of the relationship between different OMTs is presented. These SAM-Mtase sequence signatures will be useful in the identification of SAM-Mtase motifs in the hitherto unidentified proteins as well as for designing primers in the isolation of new SAM-Mtases from plants.
Joshi
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CP
Plant Biotechnology Research Center, Institute of Wood Research, School of Forestry and Wood Products, Michigan Technological University, Houghton 49931, USA.
Chiang
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VL
D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D017124:Conserved Sequence; D008780:Methyltransferases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010944:Plants / Q000201:enzymology* / Q000235:genetics*; D012436:S-Adenosylmethionine / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D012436:S-Adenosylmethionine; D008780:Methyltransferases