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Unexpected Catalytic Activity of the Regulatory Protein QacR

submitted on 16.07.2020, 14:05 and posted on 17.07.2020, 06:12 by Cora Gutiérrez de Souza, Lur Alonso-Cotchico, Manuela Bersellini, Gerard Roelfes
Natural proteins often present binding or functional promiscuity. In biocatalysis, this promiscuity has been exploited for accessing new-to-nature reactions. Here, we report an unexpected catalytic reactivity for the regulatory protein QacR from the TetR family of multidrug resistance regulators. QacR is able to catalyze the enatioselective tandem Friedel-Crafts / enantioselective protonation reaction of indoles with alpha substituted conjugated enones with up to 40% yield and 83% ee. Mutagenesis and computational studies support the hypothesis that an acidic residue in the binding pocket of the protein is responsible for protonating the enolate intermediate.


Ministerie van Onderwijs, Cultuur en Wetenschap, 024.001.035

European Research Council, no. 280010

Nederlandse Organisatie voor Wetenschappelijk Onderzoek, no.724.013.003


Email Address of Submitting Author


University of Groningen


the Netherlands

ORCID For Submitting Author


Declaration of Conflict of Interest

no conflict of interest to declare

Version Notes

this is the first version


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