# Structural and Spectroscopic Insights into Catalytic Intermediates of a [NiFe]‐hydrogenase from Group 3

## TL;DR

This study reveals the redox states and structure of a [NiFe] hydrogenase, offering insights into its catalytic mechanism for hydrogen production.

## Contribution

The study provides structural and spectroscopic evidence of a catalytic-ready state in a group 3 [NiFe] hydrogenase.

## Key findings

- A nickel seesaw coordination was identified in the catalytic-ready state of the [NiFe] hydrogenase.
- The enzyme's redox landscape was elucidated, resembling that of group 1 hydrogenases.
- The findings advance understanding of oxygen-sensitive [NiFe] enzymes' mechanisms.

## Abstract

Hydrogenases catalyze reversible H2 production and are potential models for renewable energy catalysts. Here, the full redox landscape of a group 3 [NiFe]‐hydrogenase from methanothermococcus thermolithotrophicus is elucidated, resembling group 1 enzymes. Structural and spectroscopic analyses reveal a catalytic‐ready state with nickel seesaw coordination, enabling intermediate trapping and advancing mechanistic understanding of oxygen‐sensitive [NiFe] enzymes.

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