1GP4 image
Deposition Date 2001-10-30
Release Date 2002-02-21
Last Version Date 2024-10-16
Entry Detail
PDB ID:
1GP4
Keywords:
Title:
Anthocyanidin synthase from Arabidopsis thaliana (selenomethionine substituted)
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.10 Å
R-Value Free:
0.23
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:ANTHOCYANIDIN SYNTHASE
Gene (Uniprot):LDOX
Chain IDs:A
Chain Length:356
Number of Molecules:1
Biological Source:ARABIDOPSIS THALIANA
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
MSE A MET SELENOMETHIONINE
Primary Citation

Abstact

Flavonoids are common colorants in plants and have long-established biomedicinal properties. Anthocyanidin synthase (ANS), a 2-oxoglutarate iron-dependent oxygenase, catalyzes the penultimate step in the biosynthesis of the anthocyanin class of flavonoids. The crystal structure of ANS reveals a multicomponent active site containing metal, cosubstrate, and two molecules of a substrate analog (dihydroquercetin). An additional structure obtained after 30 min exposure to dioxygen is consistent with the oxidation of the dihydroquercetin to quercetin and the concomitant decarboxylation of 2-oxoglutarate to succinate. Together with in vitro studies, the crystal structures suggest a mechanism for ANS-catalyzed anthocyanidin formation from the natural leucoanthocyanidin substrates involving stereoselective C-3 hydroxylation. The structure of ANS provides a template for the ubiquitous family of plant nonhaem oxygenases for future engineering and inhibition studies.

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Primary Citation of related structures