6AIO

Crystal structure of p-nitrophenol 4-monooxygenase PnpA from Pseudomonas putida DLL-E4

Summary for 6AIO

• Entry DOI: 10.2210/pdb6aio/pdb
• Descriptor: PnpA (2 entities in total)
• Functional Keywords: p-nitrophenol 4-monooxygenase, flavoprotein
• Biological source: Pseudomonas putida (Arthrobacter siderocapsulatus)
• Total number of polymer chains: 2
• Total formula weight: 93256.09

Authors

Chen, Q.Z.,Huang, Y.,Duan, Y.J.,Li, Z.K.,Liu, W.D.,Cui, Z.L. (deposition date: 2018-08-24, release date: 2018-10-31, Last modification date: 2023-11-22)

Primary citation

Chen, Q.Z.,Huang, Y.,Duan, Y.J.,Li, Z.K.,Cui, Z.L.,Liu, W.D.
Crystal structure of p-nitrophenol 4-monooxygenase PnpA from Pseudomonas putida DLL-E4: The key enzyme involved in p-nitrophenol degradation.
Biochem. Biophys. Res. Commun., 504:715-720, 2018

PubMed Abstract: p-Nitrophenol 4-monooxygenase PnpA, the key enzyme in the hydroquinone pathway of p-nitrophenol (PNP) degradation, catalyzes the monooxygenase reaction of PNP to p-benzoquinone in the presence of FAD and NADH. Here, we determined the first crystal structure of PnpA from Pseudomonas putida DLL-E4 in its apo and FAD-complex forms to a resolution of 2.04 Å and 2.48 Å, respectively. The PnpA structure shares a common fold with hydroxybenzoate hydroxylases, despite a low amino sequence identity of 14-18%, confirming it to be a member of the Class A flavoprotein monooxygenases. However, substrate docking studies of PnpA indicated that the residues stabilizing the substrate in an orientation suitable for catalysis are not observed in other homologous hydroxybenzoate hydroxylases, suggesting PnpA employs a unique catalytic mechanism. This work expands our understanding on the reaction mode for this enzyme class.

PubMed: 30217456
DOI: 10.1016/j.bbrc.2018.09.040

Experimental method

X-RAY DIFFRACTION (2.04 Å)