Identifying a key spot for electron mediator-interaction to tailor CO dehydrogenase's affinity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38548760.
- Also identified by DOI 10.1038/s41467-024-46909-1 and PMC identifier 10979024.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Fe‒S cluster-harboring enzymes, such as carbon monoxide dehydrogenases (CODH), employ sophisticated artificial electron mediators like viologens to serve as potent biocatalysts capable of cleaning-up industrial off-gases at stunning reaction rates. Unraveling the interplay between these enzymes and their associated mediators is essential for improving the efficiency of CODHs. Here we show the electron mediator-interaction site on ChCODHs (Ch, Carboxydothermus hydrogenoformans) using a systematic approach that leverages the viologen-reactive characteristics of superficial aromatic residues. By enhancing mediator-interaction (R57G/N59L) near the D-cluster, the strategically tailored variants exhibit a ten-fold increase in ethyl viologen affinity relative to the wild-type without sacrificing the turn-over rate (k<sub>cat</sub>). Viologen-complexed structures reveal the pivotal positions of surface phenylalanine residues, serving as external conduits for the D-cluster to/from viologen. One variant (R57G/N59L/A559W) can treat a broad spectrum of waste gases (from steel-process and plastic-gasification) containing O<sub>2</sub>. Decoding mediator interactions will facilitate the development of industrially high-efficient biocatalysts encompassing gas-utilizing enzymes.
Medical subject headings
- Electrons
- Multienzyme Complexes