This domain is found at the N-terminus of plant O-methyltransferases involved in phenylpropanoid metabolism, including caffeic acid O-methyltransferase (COMT), isoflavone O-methyltransferase (IOMT), and chalcone O-methyltransferase (ChOMT). It media ...
This domain is found at the N-terminus of plant O-methyltransferases involved in phenylpropanoid metabolism, including caffeic acid O-methyltransferase (COMT), isoflavone O-methyltransferase (IOMT), and chalcone O-methyltransferase (ChOMT). It mediates dimerisation of these enzymes, which is critical for their activity [1-4]. The dimerisation domain forms the central core of the homodimer, with the SAM-binding domains located peripherally [1,3,4]. Dimerisation buries ~30% of the total surface area of the dimer [3]. The domain also contributes to forming the back wall of the substrate binding cavity of the partner monomer [2-4]. Structurally, the dimerisation domain consists primarily of alpha-helices [1-4]. Crystal structures reveal the domain is relatively rigid compared to the more mobile SAM-binding domain, which undergoes conformational changes upon substrate binding [4].