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CATH Superfamily 2.40.128.20

Calycin beta-barrel core domain

The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was: waiting to be named.

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 28: Violaxanthin de-epoxidase, chloroplastic

There are 1 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Violaxanthin de-epoxidase. [EC: 1.23.5.1]
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.
 9 A0A384K8V4 A0A384K8V4 A0A384K8V4 B9DGR5 B9DGR5 B9DGR5 Q39249 Q39249 Q39249
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