Protocatechuate intradiol dioxygenase

Protocatechuate intradiol dioxygenase (E.C. 1.13.11.3 - Protocate-chuate oxygen 3,4-oxidoreductase (decyclizing)... 

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. 

The extradiol dioxygenases are more common than the intradiol enzymes, and are more diverse in their reactions.1379 Examples are catechol 2,3-dioxygenase (from Pseudomonas arvilla and Ps. putida) and protocatechuate 4,5-dioxygenase from Ps. testosterone These are colourless and... 

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). 

For example, the enzyme pyrocatechase effects intradiol cleavage of catechol to muconic acid [72,73,74], whereas protocatechuate 3,4-dioxygenase promotes that of protocatechuic acid (R = COOH in 37) [75,76]. Metapyrocatechase is a catalyst for proximal extradiol cleavage of catechol to a-hydroxymuconic acid e-semialdehyde (38) [77] ... 

In the mechanism of the intradiol oxygenation, the first step is the activation of catechol by coordination to a Fe(III) center. The chelate coordination of catechols in the enzymatic systems (protocatechuate 3,4-dioxygenase, 3,4-PCD) has been clarified by the X-ray analysis. in addition, the analysis indicated... 

INTRADIOL-CLEAVING DIOXYGENASES (CATECHOL 1,2-DIOXYGENASE AND PROTOCATECHUATE 3,4-DIOXYGENASE)... 

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