EC 1.13.11.8     
Accepted name: protocatechuate 4,5-dioxygenase
Reaction: 3,4-dihydroxybenzoate + O2 = 4-carboxy-2-hydroxymuconate semialdehyde
Glossary: 3,4-dihydroxybenzoate = protocatechuate
Other name(s): protocatechuate 4,5-oxygenase; protocatechuic 4,5-dioxygenase; protocatechuic 4,5-oxygenase; protocatechuate:oxygen 4,5-oxidoreductase (decyclizing); protocatechuate:oxygen 4,5-oxidoreductase (ring-opening)
Systematic name: 3,4-dihydroxybenzoate:oxygen 4,5-oxidoreductase (ring-opening)
Comments: Requires Fe2+.
References:
1.  Trippett, S., Dagley, S. and Stopher, D.A. The bacterial oxidation of nicotinic acid. Biochem. J. 76 (1960) 9.
[EC 1.13.11.8 created 1965 as EC 1.13.1.8, transferred 1972 to EC 1.13.11.8]