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Structure-Guided Modulation of the Catalytic Properties of [2Fe−2S]-Dependent Dehydratases |
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| Authors: | Okke Melse Dr Samuel Sutiono Magdalena Haslbeck Prof Gerhard Schenk Prof Iris Antes Prof Volker Sieber |
| Affiliation: | 1. Chair of Chemistry of Biogenic Resources, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, 94315 Straubing, Germany;2. Chair of Chemistry of Biogenic Resources, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, 94315 Straubing, Germany
SynBiofoundry@TUM, Technical University of Munich, Schulgasse 22, 94315 Straubing, Germany These authors contributed equally to this work.;3. Chair of Chemistry of Biogenic Resources, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Schulgasse 16, 94315 Straubing, Germany SynBiofoundry@TUM, Technical University of Munich, Schulgasse 22, 94315 Straubing, Germany;4. School of Chemistry and Molecular Biosciences, The University of Queensland, 68 Cooper Road, 4072 St. Lucia, Australia;5. SynBiofoundry@TUM, Technical University of Munich, Schulgasse 22, 94315 Straubing, Germany |
| Abstract: | The FeS cluster-dependent dihydroxyacid dehydratases (DHADs) and sugar acid-specific dehydratases (DHTs) from the ilvD/EDD superfamily are key enzymes in the bioproduction of a wide variety of chemicals. We analyzed 2Fe−2S]-dependent dehydratases in silico and in vitro, deduced functionally relevant sequence, structure, and activity relationships within the ilvD/EDD superfamily, and we propose a new classification based on their evolutionary relationships and substrate profiles. In silico simulations and analyses identified several key positions for specificity, which were experimentally investigated with site-directed and saturation mutagenesis. We thus increased the promiscuity of DHAD from Fontimonas thermophila (FtDHAD), showing >10-fold improved activity toward D-gluconate, and shifted the substrate preference of DHT from Paralcaligenes ureilyticus (PuDHT) toward shorter sugar acids (recording a six-fold improved activity toward the non-natural substrate D-glycerate). The successful elucidation of the role of important active site residues of the ilvD/EDD superfamily will further guide developments of this important biocatalyst for industrial applications. |
| Keywords: | biocatalysts bioinformatics dehydratases enzyme catalysis structure-activity relationships |