biostudies-literatureRodriguez-Macia PDeutsche ForschungsgemeinschaftFoundation for the National Institutes of HealthEinstein Stiftung BerlinMax-Planck-GesellschaftNIGMS NIH HHS16786-16794https://www.ebi.ac.uk/biostudies/studies/S-EPMC7540559biostudies-literatureUnknown59(38)[FeFe] hydrogenases are the most active H₂ converting catalysts in nature, but their extreme oxygen sensitivity limits their use in technological applications. The [FeFe] hydrogenases from sulfate reducing bacteria can be purified in an O₂ -stable state called H_inact . To date, the structure and mechanism of formation of H_inact remain unknown. Our 1.65 Å crystal structure of this state reveals a sulfur ligand bound to the open coordination site. Furthermore, in-depth spectroscopic characterization by X-ray absorption spectroscopy (XAS), nuclear resonance vibrational spectroscopy (NRVS), resonance Raman (RR) spectroscopy and infrared (IR) spectroscopy, together with hybrid quantum mechanical and molecular mechanical (QM/MM) calculations, provide dAngewandte Chemie (International ed. in English)Caught in the H_inact : Crystal Structure and Spectroscopy Reveal a Sulfur Bound to the Active Site of an O₂ -stable State of [FeFe] Hydrogenase.PMC7540559P41 GM103393EVF-2016-277EXC 2008 - 390540038GM-65440R01 GM065440IS 1476/4-1DE 1877/1-1ZE 510/2-2BI 2198/1-1Bjornsson RDeBeer SZebger IBirrell JAYoda YLorent CSpan ICramer SPGalle LMRodriguez-Macia PfalseCaught in the H_inact : Crystal Structure and Spectroscopy Reveal a Sulfur Bound to the Active Site of an O₂ -stable State of [FeFe] Hydrogenase.[FeFe] hydrogenases are the most active H₂ converting catalysts in nature, but their extreme oxygen sensitivity limits their use in technological applications. The [FeFe] hydrogenases from sulfate reducing bacteria can be purified in an O₂ -stable state called H_inact . To date, the structure and mechanism of formation of H_inact remain unknown. Our 1.65 Å crystal structure of this state reveals a sulfur ligand bound to the open coordination site. Furthermore, in-depth spectroscopic characterization by X-ray absorption spectroscopy (XAS), nuclear resonance vibrational spectroscopy (NRVS), resonance Raman (RR) spectroscopy and infrared (IR) spectroscopy, together with hybrid quantum mechanical and molecular mechanical (QM/MM) calculations, provide d2020-01-01T00:00:00Z2020 Sep2026-05-02T22:49:58.501Z2020-10-29T09:08:49ZS-EPMC75405593248897510.1002/anie.202005208