1. Biochemical and structural insights into pinoresinol hydroxylase from Pseudomonas sp.
- Author
-
Guerriere TB, Fraaije MW, and Mattevi A
- Subjects
- Substrate Specificity, Furans metabolism, Furans chemistry, Bacterial Proteins chemistry, Bacterial Proteins metabolism, Bacterial Proteins genetics, Models, Molecular, Catalytic Domain, Amino Acid Sequence, Pseudomonas enzymology, Lignans metabolism, Lignans chemistry, Mixed Function Oxygenases chemistry, Mixed Function Oxygenases metabolism, Mixed Function Oxygenases genetics
- Abstract
The vanillyl alcohol oxidase/p-cresol methylhydroxylase (VAO/PCMH) flavoprotein family comprises a broad spectrum of enzymes capable of catalyzing the oxidative bioconversions of various substrates. Among them, pinoresinol hydroxylase (PinH) from the 4-alkylphenol oxidizing subgroup initiates the oxidative degradation of (+)-pinoresinol, a lignan important for both lignin structure and plant defense. In this study, we present a detailed biochemical and structural characterization of PinH from Pseudomonas sp., with focus on its substrate specificity and product formation. PinH was expressed in E. coli and purified as FAD-containing, soluble protein. The flavoenzyme catalyzes the hydroxylation of both (+)-pinoresinol and eugenol. Structural analysis reveals its dimeric form, non-covalent flavin binding, and a large active site. AlphaFold models of the PinH-cytochrome complex demonstrate cytochrome's dual role in electron transfer and modulating PinH's conformation. A distinctive feature of PinH is a large cavity that hosts its multi-ring (+)-pinoresinol substrate. The capability of converting bulky lignans is particularly attractive for biotechnological applications aimed at producing high-value compounds from phenolic precursors. These insights expand our knowledge on the structure and mechanism of the VAO/PCMH flavoenzyme family members., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF