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 named:

"
Aldehyde oxidase/xanthine dehydrogenase, a/b hammerhead
".

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 2: Xanthine dehydrogenase/oxidase

There are 2 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
Xanthine oxidase. [EC: 1.17.3.2]
Xanthine + H(2)O + O(2) = urate + H(2)O(2).
  • Also oxidizes hypoxanthine, some other purines and pterins, and aldehydes, but is distinct from EC 1.2.3.1.
  • Under some conditions the product is mainly superoxide rather than peroxide: R-H + H(2)O + 2 O(2) = ROH + 2 O(2)(.-) + 2 H(+).
  • The mammallian enzyme predominantly exists as an NAD-dependent dehydrogenase (EC 1.17.1.4).
  • During purification the enzyme is largely converted to the O(2)- dependent xanthine oxidase form (EC 1.17.3.2).
  • The conversion can be triggered by several mechanisms, including the oxidation of cysteine thiols to form disulfide bonds (which can be catalyzed by EC 1.8.4.7 in the presence of glutathione disulfide) or limited proteolysis, which results in irreversible conversion.
  • The conversion can also occur in vivo.
  • Formerly EC 1.1.3.22 and EC 1.2.3.2.
6 P22985 P47989 P47990 P80457 Q00519 Q9MYW6
Xanthine dehydrogenase. [EC: 1.17.1.4]
Xanthine + NAD(+) + H(2)O = urate + NADH.
  • Acts on a variety of purines and aldehydes, including hypoxanthine.
  • The mammalian enzyme can also convert all-trans retinol to all-trans- retinoate, while the substrate is bound to a retinoid-binding protein.
  • The enzyme from eukaryotes contains [2Fe-2S], FAD and a molybdenum center.
  • The mammallian enzyme predominantly exists as the NAD-dependent dehydrogenase (EC 1.17.1.4).
  • During purification the enzyme is largely converted to an O(2)- dependent form, EC 1.17.3.2.
  • The conversion can be triggered by several mechanisms, including the oxidation of cysteine thiols to form disulfide bonds (which can be catalyzed by EC 1.8.4.7 in the presence of glutathione disulfide) or limited proteolysis, which results in irreversible conversion.
  • The conversion can also occur in vivo.
  • Formerly EC 1.2.1.37 and EC 1.1.1.204.
6 P22985 P47989 P47990 P80457 Q00519 Q9MYW6