7WH9

holo structure of emodin 1-OH O-methyltransferase complex with emodin and S-Adenosyl-L-homocysteine

Summary for 7WH9

• Entry DOI: 10.2210/pdb7wh9/pdb
• Descriptor: O-methyltransferase gedA, 3-METHYL-1,6,8-TRIHYDROXYANTHRAQUINONE, S-ADENOSYL-L-HOMOCYSTEINE, ... (4 entities in total)
• Functional Keywords: o-methyltransferase, emodin, transferase
• Biological source: Aspergillus terreus
• Total number of polymer chains: 3
• Total formula weight: 170082.25

Authors

Liang, Y.J.,Lu, X.F.,Qi, F.F.,Xue, Y.Y. (deposition date: 2021-12-30, release date: 2023-01-11, Last modification date: 2024-05-29)

Primary citation

Xue, Y.,Liang, Y.,Zhang, W.,Geng, C.,Feng, D.,Huang, X.,Dong, S.,Zhang, Y.,Sun, J.,Qi, F.,Lu, X.
Characterization and Structural Analysis of Emodin- O -Methyltransferase from Aspergillus terreus.
J.Agric.Food Chem., 70:5728-5737, 2022

PubMed Abstract: All -methylated derivatives of emodin, including physcion, questin, and 1--methylemodin, show potential antifungal activities. Notably, emodin and questin are two pivotal intermediates of geodin biosynthesis in . Although most of the geodin biosynthetic steps have been investigated, the key -methyltransferase (OMT) responsible for the -methylation of emodin to generate questin has remained unidentified. Herein, through phylogenetic tree analysis and biochemical assays, the long-sought class II emodin--methyltransferase GedA has been functionally characterized. Additionally, the catalytic mechanism and key residues at the catalytic site of GedA were elucidated by enzyme-substrate-methyl donor analogue ternary complex crystal structure determination and site-directed mutagenesis. As we demonstrate, GedA adopts a typical general acid/base (E446/H373)-mediated transmethylation mechanism. In particular, residue D374 is also crucial for efficient catalysis through blocking the formation of intramolecular hydrogen bonds in emodin. This study will facilitate future engineering of GedA for the production of physcion or other site-specific -methylated anthraquinone derivatives with potential applications as biopesticides.

PubMed: 35475366
DOI: 10.1021/acs.jafc.2c01281

Experimental method

X-RAY DIFFRACTION (2.803 Å)