Hydrogenases are intriguing metalloenzymes that catalyze the reversible activation of H2. These biocatalysts are being explored for various biotechnological applications and are attracting increasing attention due to their eco-friendly potential, especially in the context of future energy solutions. However, crucial details of their biosynthesis, which involves a complex protein machinery, and their reaction mechanism remain to be fully understood.
The UniSysCat teams, led by Oliver Lenz, Juri Rappsilber, Christian Limberg, Maria Andrea Mroginski, and Ingo Zebger, have joined forces to elucidate how the cellular machinery assembles the ‘iron fragment’ of the catalytic center of [NiFe]-hydrogenase. By combining advanced experimental and theoretical methods, they have gained insight into the "construction site" where two proteins, HypC and HypD, with the help of ATP, securely load the labile Fe(CN)2CO fragment into the apo form of [NiFe]-hydrogenase.
Using biochemical methods along with spectroscopic techniques such as infrared (IR), Mössbauer spectroscopy, and nuclear resonance vibrational spectroscopy (NRVS), combined with computational chemistry, the team uncovered how the Fe(CN)2CO fragment is coordinated by the HypC and HypD maturases. The team also discovered an unusual role for ATP – the universal energy carrier in living organisms – which aids in transferring the iron fragment to [NiFe]-hydrogenase by binding to a cleft in the HypCD complex (rather than hydrolyzing, as usually observed).
These findings deepen our understanding of how complex metal cofactors are assembled and pave the way for broader use of hydrogenases in biotechnology.
This study has been published in the Journal of the American Chemical Society: A. Kwiatkowski et al., J. Am. Chem. Soc. 2024, 146, 45, 30976–30989, https://doi.org/10.1021/jacs.4c09791