1GP6: Anthocyanidin Synthase From Arabidopsis Thaliana Complexed With Trans-dihydroquercetin (with 30 Min Exposure To O2)

Citation:
Abstract
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.
PDB ID: 1GP6Download
MMDB ID: 18661
PDB Deposition Date: 2001/10/30
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.75  Å
Source Organism:
Similar Structures:
Biological Unit for 1GP6: monomeric; determined by author and by software (PQS)
Molecular Components in 1GP6
Label Count Molecule
Protein (1 molecule)
1
Leucoanthocyanidin Dioxygenase(Gene symbol: LDOX)
Molecule annotation
Chemicals (6 molecules)
1
1
2
2
3
1
4
1
5
1
* Click molecule labels to explore molecular sequence information.

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