Extradiol dioxygenase that opens up the cyclic ring of DOPA between carbons 4 and 5 thus producing an unstable seco-DOPA that rearranges non-enzymatically to betalamic acid. Can also catalyze the formation of muscaflavin (a pigment found in the hygrocybe mushrooms family and of some amanita species only) by a 2,3-extradiol cleavage of DOPA. Pigment biosynthesis; betalain biosynthesis. Homodimer. Expressed at high level in coloured cap tissue and at least 10 times lower level in the stipe. Pretty pigments - Issue 1 of September 2000