4-hydroxybenzoate 3-monooxygenase

In enzymology, a 4-hydroxybenzoate 3-monooxygenase (EC 1.14.13.2) is an enzyme that catalyzes the chemical reaction

4-hydroxybenzoate + NADPH + H⁺ + O₂ protocatechuate + NADP⁺ + H₂O

The 4 substrates of this enzyme are 4-hydroxybenzoate, NADPH, H⁺, and O₂, whereas its 3 products are protocatechuate, NADP⁺, and H₂O.

This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with NADH or NADPH as one donor, and incorporation of one atom o oxygen into the other donor. The systematic name of this enzyme class is 4-hydroxybenzoate,NADPH:oxygen oxidoreductase (3-hydroxylating). Other names in common use include p-hydroxybenzoate hydrolyase, p-hydroxybenzoate hydroxylase, 4-hydroxybenzoate 3-hydroxylase, 4-hydroxybenzoate monooxygenase, 4-hydroxybenzoic hydroxylase, p-hydroxybenzoate-3-hydroxylase, p-hydroxybenzoic acid hydrolase, p-hydroxybenzoic acid hydroxylase, and p-hydroxybenzoic hydroxylase. This enzyme participates in benzoate degradation via hydroxylation and 2,4-dichlorobenzoate degradation. It employs one cofactor, FAD.

Structural studies

As of late 2007, 31 structures have been solved for this class of enzymes, with PDB accession codes 1BF3, 1BGJ, 1BGN, 1BKW, 1CC4, 1CC6, 1CJ2, 1CJ3, 1CJ4, 1D7L, 1IUS, 1IUT, 1IUU, 1IUV, 1IUW, 1IUX, 1K0I, 1K0J, 1K0L, 1PBB, 1PBC, 1PBD, 1PBE, 1PBF, 1PDH, 1PHH, 1PXA, 1PXB, 1PXC, 1YKJ, and 2PHH.

References

• Hosokawa K, Stanier RY (1966). "Crystallization and properties of p-hydroxybenzoate hydroxylase from Pseudomonas putida". J. Biol. Chem. 241 (10): 2453–60. PMID 4380381. 
• Howell LG, Spector T, Massey V (1972). "Purification and properties of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens". J. Biol. Chem. 247 (13): 4340–50. PMID 4402514. 
• Spector T, Massey V (1972). "Studies on the effector specificity of p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens". J. Biol. Chem. 247 (14): 4679–87. PMID 4402938. 
• Spector T, Massey V (1972). "p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens. Evidence for an oxygenated flavin intermediate". J. Biol. Chem. 247 (17): 5632–6. PMID 4403446. 
• Spector T, Massey V (1972). "p-Hydroxybenzoate hydroxylase from Pseudomonas fluorescens Reactivity with oxygen". J. Biol. Chem. 247 (22): 7123–7. PMID 4404745. 
• Seibold B, Matthes M, Eppink MH, Lingens F, Van Berkel WJ, Muller R (1996). "4-Hydroxybenzoate hydroxylase from Pseudomonas sp. CBS3 Purification, characterization, gene cloning, sequence analysis and assignment of structural features determining the coenzyme specificity". Eur. J. Biochem. 239 (2): 469–78. doi:10.1111/j.1432-1033.1996.0469u.x. PMID 8706756.