7QR6

Stilbene dioxygenase (NOV1) from Novosphingobium aromaticivorans: Ser283Phe mutant

Summary for 7QR6

• Entry DOI: 10.2210/pdb7qr6/pdb
• Descriptor: Dioxygenase, FE (III) ION, OXYGEN MOLECULE, ... (4 entities in total)
• Functional Keywords: iron, dioxygenase, biocatalysis, carotenoid cleavage oxygenases, non-heme iron proteins, biorefinery, lignin valorization, thermostability, oxidoreductase
• Biological source: Novosphingobium aromaticivorans
• Total number of polymer chains: 3
• Total formula weight: 166897.25

Authors

Alvigini, L.,Mattevi, A. (deposition date: 2022-01-10, release date: 2022-08-10, Last modification date: 2024-02-07)

Primary citation

De Simone, M.,Alvigini, L.,Alonso-Cotchico, L.,Brissos, V.,Caroli, J.,Lucas, M.F.,Monza, E.,Melo, E.P.,Mattevi, A.,Martins, L.O.
Rationally Guided Improvement of NOV1 Dioxygenase for the Conversion of Lignin-Derived Isoeugenol to Vanillin.
Biochemistry, 62:419-428, 2023

PubMed Abstract: Biocatalysis is a key tool in both green chemistry and biorefinery fields. NOV1 is a dioxygenase that catalyzes the one-step, coenzyme-free oxidation of isoeugenol into vanillin and holds enormous biotechnological potential for the complete valorization of lignin as a sustainable starting material for biobased chemicals, polymers, and materials. This study integrates computational, kinetic, structural, and biophysical approaches to characterize a new NOV1 variant featuring improved activity and stability compared to those of the wild type. The S283F replacement results in a 2-fold increased turnover rate () for isoeugenol and a 4-fold higher catalytic efficiency (/) for molecular oxygen compared to those of the wild type. Furthermore, the variant exhibits a half-life that is 20-fold higher than that of the wild type, which most likely relates to the enhanced stabilization of the iron cofactor in the active site. Molecular dynamics supports this view, revealing that the S283F replacement decreases the optimal p and favors conformations of the iron-coordinating histidines compatible with an increased level of binding to iron. Importantly, whole cells containing the S283F variant catalyze the conversion of ≤100 mM isoeugenol to vanillin, yielding >99% molar conversion yields within 24 h. This integrative strategy provided a new enzyme for biotechnological applications and mechanistic insights that will facilitate the future design of robust and efficient biocatalysts.

PubMed: 35687874
DOI: 10.1021/acs.biochem.2c00168

Experimental method

X-RAY DIFFRACTION (2.9 Å)