Tracking W-Formate Dehydrogenase Structural Changes During Catalysis and Enzyme Reoxidation

Funding Information: This work is financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project PTDC/BII-BBF/2050/2020, Research Units Applied Molecular Biosciences—UCIBIO (UIDP/04378/2020 and UIDB/04378/2020) and MOSTMICRO-ITQB (UIDB/04612/2020 and UIDP/04612/2020) and Associate Laboratories Institute for Health and Bioeconomy—i4HB (LA/P/0140/2020) and LS4FUTURE (LA/P/0087/2020). Publisher Copyright: © 2022 by the authors. ; Metal-dependent formate dehydrogenases (Fdh) catalyze the reversible conversion of CO2 to formate, with unrivalled efficiency and selectivity. However, the key catalytic aspects of these enzymes remain unknown, preventing us from fully benefiting from their capabilities in terms of biotechnological applications. Here, we report a time-resolved characterization by X-ray crystallography of the Desulfovibrio vulgaris Hildenborough SeCys/W-Fdh during formate oxidation. The results allowed us to model five different intermediate structures and to chronologically map the changes occurring during enzyme reduction. Formate molecules were assigned for the first time to populate the catalytic pocket of a Fdh. Finally, the redox reversibility of DvFdhAB in crystals was confirmed by reduction and reoxidation structural studies. ; publishersversion ; published