3,4-Protocatechuate reactions catalyzed

This iron-dependent enzyme [EC 1.13.11.3], also known as protocatechuate oxygenase, catalyzes the reaction of 3,4-dihydroxybenzoate with dioxygen to produce 3-carboxy-d5, CK-muconate. 

Gentisic acid is also a substrate for a specific inducible enzyme of Pseudomonas (Lack, 1959). The nature of the reaction catalyzed by this enzyme appears to be similar to that of the catechol 2 3-oxygenase and protocatechuic 4 5-oxygenase. A partially purified enzyme was found to form maleylpyruvate as the first product (Fig. 10). Subsequent isomeri-... 

Pyrocatechase31 and protocatechuate 3,4-dioxygenase 86, both of which are typical examples of the intradiol cleavage, catalyze the reaction shown in Eqs. (2) and (12), respectively. 

This enzyme is colorless and contains the ferrous form of iron as the sole cofactor53,54 3,4-Dihydroxyphenylacetate 2,3-dioxygenase catalyzes the reaction shown in Eq. (14) and is an example of the proximal extradiol cleavage89-91. Protocatechuate 4,5-dioxygenase catalyzes the reaction shown in Eq.(15) and is an example of the distal extradiol cleavage92-94. ... 

The intradiol-cleaving enzymes represented by catechol 1,2-dioxygenase and protocatechuate 3,4-dioxygenase (PCD) catalyze the reactions shown in Figure 4. Both enzymes have iron(III) active sites and are spectroscopically well characterized. The enzymes exhibit a distinct bmgundy red color (Xmax 460 nm, 450 3500 cm ) that is... 

The intradiol cleaving catechol dioxygenases are bacterial iron-containing enzymes that serve as a component of nature s mechanism for degrading aromatic compounds in the environment. These enzymes, represented by catechol 1,2-dioxygenase (CTD) and protocatechuate(3,4-dihydroxybenzoate) 3,4-dioxygenase (PCD), catalyze the reaction... 

Protocatechuate 3,4-dioxygenase. Crystalline preparations of the enzyme were obtained as described previously (2). The enzyme catalyzes the intradiol cleavage of protocatechuic acid with the insertion of two atoms of molecular oxygen to form /8-carboxy cis,cis-muconic acid (Reaction 3). 

Tracer studies of the fate of oxygen consumed during protocate-chuic acid cleavage have not been carried ocit, but because of oxygen stoichiometry, dependence of the enzyme upon ferrous ions, and resemblance of the over-all reaction to those catalyzed by pyrocate-chase, homogentisate oxidase, and 3-hydroxyanthranilate oxidase (compare 171), it is reasonable to classify protocatechuic acid oxidase as an oxygen transferase. 

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