1FPQ: Crystal Structure Analysis Of Selenomethionine Substituted Chalcone O- Methyltransferase

Chalcone O-methyltransferase (ChOMT) and isoflavone O-methyltransferase (IOMT) are S-adenosyl-l-methionine (SAM) dependent plant natural product methyltransferases involved in secondary metabolism in Medicago sativa (alfalfa). Here we report the crystal structure of ChOMT in complex with the product S-adenosyl-l-homocysteine and the substrate isoliquiritigenin (4,2',4'-trihydroxychalcone) refined to 1.8 A as well as the crystal structure of IOMT in complex with the products S-adenosyl-l-homocysteine and isoformononetin (4'-hydroxy-7-methoxyisoflavone) refined to 1.4 A. These two OMTs constitute the first plant methyltransferases to be structurally characterized and reveal a novel oligomerization domain and the molecular determinants for substrate selection. As such, this work provides a structural basis for understanding the substrate specificity of the diverse family of plant OMTs and facilitates the engineering of novel activities in this extensive class of natural product biosynthetic enzymes.
PDB ID: 1FPQDownload
MMDB ID: 15544
PDB Deposition Date: 2000/8/31
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 1FPQ: dimeric; determined by author and by software (PISA,PQS)
Molecular Components in 1FPQ
Label Count Molecule
Proteins (2 molecules)
Isoliquiritigenin 2'-o-methyltransferase
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

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