X-ray Crystallography and Vibrational Spectroscopy Reveal the Key Determinants of Biocatalytic Dihydrogen Cycling by [NiFe] Hydrogenases
Journalartikel
Details zur Publikation
Autor*innen: Ilina Y., Lorent C., Katz S., Jeoung J.H., Shima S., Horch M., Zebger I., Dobbek H.
Zeitschrift: Angewandte Chemie International Edition
Jahr der Veröffentlichung: 2019
Bandnummer: 58
Heftnummer: 51
Seiten: 18710-18714
Verlag: Wiley-VCH Verlag
ISSN: 1433-7851
eISSN: 1521-3773
URL: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85074565065&origin=inward
Sprachen: English-Great Britain
Beschreibung
[NiFe] hydrogenases are complex model enzymes for the reversible cleavage of dihydrogen (H2). However, structural determinants of efficient H2 binding to their [NiFe] active site are not properly understood. Here, we present crystallographic and vibrational-spectroscopic insights into the unexplored structure of the H2-binding [NiFe] intermediate. Using an F420-reducing [NiFe]-hydrogenase from Methanosarcina barkeri as a model enzyme, we show that the protein backbone provides a strained chelating scaffold that tunes the [NiFe] active site for efficient H2 binding and conversion. The protein matrix also directs H2 diffusion to the [NiFe] site via two gas channels and allows the distribution of electrons between functional protomers through a subunit-bridging FeS cluster. Our findings emphasize the relevance of an atypical Ni coordination, thereby providing a blueprint for the design of bio-inspired H2-conversion catalysts.