Term Name:	tetrahydroxypteridine cycloisomerase activity
Synonyms:	tetrahydroxypteridine lyase (isomerizing)
Definition:	Catalysis of the reaction: tetrahydroxypteridine = H+ + xanthine-8-carboxylate.
Ontology:	GO: Molecular Function [GO:0050329]    QuickGO    AmiGO