CATH Classification
| Level | CATH Code | Description |
|---|---|---|
|
2 | Mainly Beta |
|
2.40 | Beta Barrel |
|
2.40.128 | Lipocalin |
|
2.40.128.20 | Calycin beta-barrel core domain |
Domain Context
CATH Clusters
| Superfamily | 2.40.128.20 |
| Functional Family | Violaxanthin de-epoxidase, chloroplastic |
Enzyme Information
| 1.23.5.1 |
Violaxanthin de-epoxidase.
based on mapping to UniProt Q39249
Violaxanthin + 2 L-ascorbate = antheraxanthin + 2 L-dehydroascorbate + H(2)O.
-!- Along with EC 1.14.15.21, this enzyme forms part of the xanthophyll (or violaxanthin) cycle for controlling the concentration of zeaxanthin in chloroplasts. -!- It is activated by a low pH of the thylakoid lumen (produced by high light intensity). -!- Zeaxanthin induces the dissipation of excitation energy in the chlorophyll of the light-harvesting protein complex of photosystem II. -!- In higher plants the enzyme reacts with all-trans-diepoxides, such as violaxanthin, and all-trans-monoepoxides, but in the alga Mantoniella squamata, only the diepoxides are good substrates. -!- Formerly EC 1.10.99.3.
|
UniProtKB Entries (1)
| Q39249 |
VDE_ARATH
Arabidopsis thaliana
Violaxanthin de-epoxidase, chloroplastic
|
PDB Structure
| PDB | 3CQR |
| External Links | |
| Method | X-RAY DIFFRACTION |
| Organism | |
| Primary Citation |
A structural basis for the pH-dependent xanthophyll cycle in Arabidopsis thaliana.
Plant Cell
|