# Biosynthesis and Reactivity of the Active Site of the FeFe Hydrogenases

> **NIH NIH R01** · UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN · 2023 · $315,901

## Abstract

Project Summary
Hydrogenase enzymes are pervasive, being found in bacteria, archaea, and some
higher organisms. These enzymes are hosted by some pathogens, often in anaerobic
environments including the human gut. The hydrogenases mediate the most
fundamental chemical reaction: the interconversion of H2 with protons and reducing
equivalents. The enzymes are structurally exceptional with an array of distinctive
cofactors, especially the site of H2 binding and release. Interest in such enzymes stems
from three angles: the possibility that some pathogens could be controlled rationally, the
excitement about their unusual structures, and the commercial implications of hydrogen
production/oxidation in the context of fuel cells.
Two major classes of hydrogenases exist, [NiFe]- and [FeFe]-hydrogenases. This
project is almost exclusively focused on the latter. More specifically, this project aims to
elucidate the biosynthesis of the active site of [FeFe] enzymes, the faster hydrogenase
and the one most amenable to development for other applications. This project is timely
because we have just defined the sequence by which the three maturase enzymes build
the active site. In parallel with their unusual structures, the construction (biosynthesis)
of the active site proceeds unusually.
The first subproject aims to make the first Fe-containing intermediate, "Compound B".
The next two projects tackle how B is converted to an inorganic Fe-S-CN-CO monomer.
The fourth project examines the coupling of this monomer to give an inorganic dimer.
The final and fifth project examines the retrofitting of this Fe2 entity with an organic
cofactor.
In this program collateral projects address allied themes of still broader interest. One
involves expanding our knowledge of iron complexes of amino acids. Another
contributes to the biosynthesis of [NiFe]-hydrogenases. One spin-off project critically
examines the premises of the Iron-Sulfur Theory of the origin of life by examination of
the first Fe-S-CN-CO complexes.

## Key facts

- **NIH application ID:** 10693280
- **Project number:** 5R01GM061153-22
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
- **Principal Investigator:** Thomas Rauchfuss
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $315,901
- **Award type:** 5
- **Project period:** 2000-07-01 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10693280

## Citation

> US National Institutes of Health, RePORTER application 10693280, Biosynthesis and Reactivity of the Active Site of the FeFe Hydrogenases (5R01GM061153-22). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10693280. Licensed CC0.

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