1kyw

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spinqualitylabelsall models 1kyw, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure Analysis of Caffeic Acid/5-hydroxyferulic acid 3/5-O-methyltransferase in complex with 5-hydroxyconiferaldehyde

Overview

Caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase (COMT) from, alfalfa is an S-adenosyl-L-Met-dependent O-methyltransferase involved in, lignin biosynthesis. COMT methylates caffeoyl- and, 5-hydroxyferuloyl-containing acids, aldehydes, and alcohols in vitro while, displaying a kinetic preference for the alcohols and aldehydes over the, free acids. The 2.2-A crystal structure of COMT in complex with, S-adenosyl-L-homocysteine (SAH) and ferulic acid (ferulate form), as well, as the 2.4-A crystal structure of COMT in complex with SAH and, 5-hydroxyconiferaldehyde, provide a structural understanding of the, observed substrate preferences. These crystal structures identify residues, lining the active site surface that contact the substrates. Structurally, guided site-directed mutagenesis of active site residues was performed, with the goal of altering the kinetic preferences for physiological, substrates. The kinetic parameters of the COMT mutants versus wild-type, enzyme are presented, and coupled with the high-resolution crystal, structures, they will serve as a starting point for the in vivo, manipulation of lignin monomers in transgenic plants. Ultimately, this, structurally based approach to metabolic engineering will allow the, further alteration of the lignin biosynthetic pathway in agronomically, important plants. This approach will lead to a better understanding of the, in vivo operation of the potential metabolic grid for monolignol, biosynthesis.

About this Structure

1KYW is a Single protein structure of sequence from Medicago sativa with SAH and HFL as ligands. Active as Caffeate O-methyltransferase, with EC number 2.1.1.68 Full crystallographic information is available from OCA.

Reference

Structural basis for the modulation of lignin monomer methylation by caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase., Zubieta C, Kota P, Ferrer JL, Dixon RA, Noel JP, Plant Cell. 2002 Jun;14(6):1265-77. PMID:12084826

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