Structural and Functional Characterization of 4‐Hydroxyphenylacetate 3‐Hydroxylase from Escherichia coli. (8th October 2019)

• Record Type: Journal Article
• Authors: Deng, Yifan; Faivre, Bruno; Back, Olivier; Lombard, Murielle; Pecqueur, Ludovic; Fontecave, Marc
• Is Part Of: Chembiochem. Volume 21:Number 1/2(2020)
• Page Start: 163
• Page End: 170
• Publication Date: 2019-10-08
• Subjects: enzymes -- green chemistry -- hydroxylation -- natural products -- synthesis design; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pharmaceutical chemistry -- Periodicals; 572
• DOI: 10.1002/cbic.201900277
• Languages: English
• ISSNs: 1439-4227

Abstract

Abstract: The hydroxylation of phenols into polyphenols, which are valuable chemicals and pharmaceutical products, is a challenging reaction. The search for green synthetic processes has led to considering microorganisms and pure hydroxylases as catalysts for phenol hydroxylation. Herein, we report the structural and functional characterization of the flavin adenine dinucleotide (FAD)‐dependent 4‐hydroxyphenylacetate 3‐monooxygenase from Escherichia coli, named HpaB. It is shown that this enzyme enjoys a relatively broad substrate specificity, which allows the conversion of a number of non‐natural phenolic compounds, such as tyrosol, hydroxymandelic acid, coumaric acid, hydroxybenzoic acid and its methyl ester, and phenol, into the corresponding catechols. The reaction can be performed by using a simple chemical assay based on formate as the electron donor and the organometallic complex [Rh(bpy)Cp*(H2 O)] 2+ (Cp*: 1, 2, 3, 4, 5‐pentamethylcyclopentadiene, bpy: 2, 2′‐bipyridyl) as the catalyst for FAD reduction. The availability of a crystal structure of HpaB in complex with FAD at 1.8 Å resolution opens up the possibility of the rational tuning of the substrate specificity and activity of this interesting class of phenol hydroxylases. Abstract : More than a FAD : The structural and functional characterization of HpaB from E. coli, which is a FAD‐dependent 4‐hydroxyphenylacetate 3‐monooxygenase, is reported. This enzyme enjoys a relatively broad substrate specificity that is useful for the conversion of diverse phenolic compounds into their corresponding catechols.