Structure and mechanism of Pseudomonas aeruginosa PA0254/HudA, a prFMN-dependent pyrrole-2-carboxylic acid decarboxylase linked to virulence

DOI: 10.1021/acscatal.0c05042

Authors: Karl A. P. Payne (University of Manchester) , Stephen A. Marshall (University of Manchester) , Karl Fisher (University of Manchester) , Stephen E. J. Rigby (University of Manchester) , Matthew J. Cliff (University of Manchester) , Reynard Spiess (University of Manchester) , Diego M. Cannas (University of Manchester) , Igor Larrosa (University of Manchester) , Sam Hay (University of Manchester) , David Leys (Manchester Institute of Biotechnology, University of Manchester; Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Catalysis

State: Published (Approved)
Published: February 2021
Diamond Proposal Number(s): 12788

Abstract: The UbiD family of reversible (de)carboxylases depends on the recently discovered prenylated-FMN (prFMN) cofactor for activity. The model enzyme ferulic acid decarboxylase (Fdc1) decarboxylates unsaturated aliphatic acids via a reversible 1,3-cycloaddition process. Protein engineering has extended the Fdc1 substrate range to include (hetero)aromatic acids, although catalytic rates remain poor. This raises the question how efficient decarboxylation of (hetero)aromatic acids is achieved by other UbiD family members. Here, we show that the Pseudomonas aeruginosa virulence attenuation factor PA0254/HudA is a pyrrole-2-carboxylic acid decarboxylase. The crystal structure of the enzyme in the presence of the reversible inhibitor imidazole reveals a covalent prFMN–imidazole adduct is formed. Substrate screening reveals HudA and selected active site variants can accept a modest range of heteroaromatic compounds, including thiophene-2-carboxylic acid. Together with computational studies, our data suggests prFMN covalent catalysis occurs via electrophilic aromatic substitution and links HudA activity with the inhibitory effects of pyrrole-2-carboxylic acid on P. aeruginosa quorum sensing.

Journal Keywords: decarboxylase; enzyme mechanism; flavin chemistry; prFMN; Pseudomonas aeruginosa; quorum sensing; pyrrole-2-carboxylic acid

Subject Areas: Chemistry, Biology and Bio-materials


Instruments: I03-Macromolecular Crystallography , I04-Macromolecular Crystallography

Documents:
acscatal.0c05042.pdf

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