Identification of the proteins composing the CO dehydrogenase and furfurylformamide dehydrogenase enzymes purified from a thermophilic ethane-oxidizing microbial consortium

ABSTRACT: Identification of the peptides composing the enriched multisubunit enzymes natively purified from the microbial enrichment, based on gel bands obtained by native electrophoresis. The anaerobic oxidation of alkanes is a microbial process occurring in deep-sea hydrocarbon seeps that plays a key ecological role in these exotic niches. The metabolic capacity of anaerobic ethane oxidation, involving uncharted biochemistry, was reported in two archaeal species depending on sulfate-reducing partner bacteria. This study deciphers the molecular basis of the CO2-generating steps of ethanotrophy by characterising the native archaeal enzymes isolated from a thermophilic enrichment. While other microorganisms couple these steps to ferredoxin reduction, we found that the CO-dehydrogenase and the formylmethanofuran-dehydrogenase are bound to F420-reductase modules. The crystal structures of these multi-metalloenzyme complexes revealed electronic bridges coupling C1-oxidation to F420-reduction. Accordingly, both systems exhibit robust F420-reductase activities, which are not detected in methanogenic or methanotrophic relative organisms. We speculate that the whole catabolism of these archaea is reoriented towards F420-reduction, which facilitates the electron transfer to the sulfate-reducing partner, therefore representing the driving force of ethanotrophy.

INSTRUMENT(S): Orbitrap Exploris 480

ORGANISM(S): Candidatus Ethanoperedens Thermophilum

SUBMITTER: Barbara Steigenberger  

LAB HEAD: Tristan Wagner

PROVIDER: PXD054507 | Pride | 2024-09-23

REPOSITORIES: Pride