X‐ray Crystallography and Vibrational Spectroscopy Reveal the Key Determinants of Biocatalytic Dihydrogen Cycling by [NiFe] Hydrogenases

Yulia Ilina, Christian Lorent, Sagie Katz, Jae-Hun Jeoung, Seigo Shima, Marius Horch, Ingo Zebger, Holger Dobbek, Humboldt-Universität Zu Berlin
[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
more » ... ng 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.
doi:10.18452/24627 fatcat:xqshfgnbingmpb6yr6gp324ysm