# Engineering the Electron Relay in [FeFe]-Hydrogenase Enhances Electrocatalytic H2 Evolution

## TL;DR

Scientists improved a natural enzyme's ability to produce hydrogen gas by modifying its structure, making it easier to use in biotechnology.

## Contribution

The study engineered a [FeFe]-hydrogenase to simplify its structure while maintaining high catalytic performance.

## Key findings

- Truncated variants of [FeFe]-hydrogenase retain high electrocatalytic H2 production activity.
- Modified enzyme variants are easier to produce and maintain essential properties.
- Engineering the F-domain reduces complexity without compromising function.

## Abstract

H2 is
an ideal energy vector, but catalysts for its
clean production from water are inefficient or expensive. [FeFe]-hydrogenases
are the most active H2-converting catalysts in nature,
using a unique organometallic active site finely tuned by the protein
matrix. M3 type [FeFe]-hydrogenases from Clostridium
pasteurianum and Clostridium acetobutylicum are exceptionally active for H2 production, and less
O2 sensitive than most other types of [FeFe]-hydrogenases,
making them attractive targets for biotechnology. However, they are
more challenging to work with because of their large size and the
number of iron–sulfur clusters. Here, the [FeFe]-hydrogenase
from C. acetobutylicum was systematically
engineered to truncate each iron–sulfur-containing region of
the F-domain, yielding smaller and easier-to-produce catalytic systems.
Detailed characterization revealed that these variants retain high
electrocatalytic performance and other essential properties of the
natural enzyme.