The enzyme nitrogenase uses a suite of complex metallocofactors to reduce dinitrogen (N) to ammonia. Mechanistic details of this reaction remain sparse. We report a 1.83-angstrom crystal structure of the nitrogenase molybdenum-iron (MoFe) protein captured under physiological N turnover conditions. This structure reveals asymmetric displacements of the cofactor belt sulfurs (S2B or S3A and S5A) with distinct dinitrogen species in the two αβ dimers of the protein. The sulfur-displaced sites are distinct in the ability of protein ligands to donate protons to the bound dinitrogen species, as well as the elongation of either the Mo-O5 (carboxyl) or Mo-O7 (hydroxyl) distance that switches the Mo-homocitrate ligation from bidentate to monodentate. These results highlight the dynamic nature of the cofactor during catalysis and provide evidence for participation of all belt-sulfur sites in this process.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8410457 | PMC |
| http://dx.doi.org/10.1126/science.aaz6748 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Amorphous Pd nanoparticles inside ethylenediamine-based nanocomposite for high N-selectivity of nitrate reduction.
J Hazard Mater
January 2025
College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China. Electronic address:
Catalytic reduction of nitrate to dinitrogen (N) by noble metals stands as a feasible and promising manner to address the biological and environmental issues associated with nitrate pollution; however, nitrate reduction under single noble-metal catalyzation remains substantially stuck because of the low adsorption enthalpy of noble metal toward nitrate. Tailoring the formation (crystal structure and particle size) of catalytical metal particles, coupled with a more direct electron donating pattern, provides a potential solution for the main challenge in reduction efficiency and selectivity. In this study, we assembled a Pd-based nanocomposite (Pda@EC) by subtly regulating the embedded Pd nanoparticles inside a porous substrate self-sufficient in electron donator (i.
View Article and Find Full Text PDFUnusual Inertness of a Ta Cluster in Dinitrogen Reactions.
J Phys Chem Lett
January 2025
Beijing National Laboratory for Molecular Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Article Synopsis
- Clusters are key for understanding how the structure of materials relates to their properties, especially at the atomic level.
- There’s growing interest in stable clusters, but this isn’t the same for all transition metal clusters.
- Research on pure tantalum clusters showed that their stability and interactions with dinitrogen involve complex electronic behaviors and reaction dynamics, aiding insights for creating materials that can effectively resist nitrogen.
Selective oxidation of ammonium to dinitrogen by a novel catalytic ozonation system: Regulating the N selectivity by sulfite.
Chemosphere
February 2025
Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, PR China.
The selective oxidation of NH-N into dinitrogen (N) is still a challenge. Currently, traditional advanced oxidation processes often involve in the chlorine free radicals to increase the selectivity of NH-N oxidation products towards N but is usually accompanied by the production of many toxic disinfection by-product. Herein, we reported a novel catalytic ozonation system (UV/O/MgO/NaSO) for selective NH-N oxidation based on the reducing capability and photochemical properties of NaSO.
View Article and Find Full Text PDFFormation and Fate of Reactive Nitrogen during Biological Nitrogen Removal from Water: Important Yet Often Ignored Chemical Aspects of the Nitrogen Cycle.
Environ Sci Technol
December 2024
Center for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, 8000 Aarhus C, Denmark.
Hydroxylamine, nitrous acid, and nitric oxide are obligate intermediates or side metabolites in different nitrogen-converting microorganisms. These compounds are unstable and susceptible to the formation of highly reactive nitrogen species, including nitrogen dioxide, dinitrogen trioxide, nitroxyl, and peroxynitrite. Due to the high reactivity and cytotoxicity, the buildup of reactive nitrogen can affect the interplay of microorganisms/microbial processes, stimulate the reactions with organic compounds like organic micropollutants (OMP) and act as the precursors of nitrous oxide (NO).
View Article and Find Full Text PDFControlling the Reaction Pathways of Mixed NOH Reactants in Plasma-Electrochemical Ammonia Synthesis.
J Am Chem Soc
December 2024
Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260, United States.
Electrochemical activation of dinitrogen (N) is notoriously challenging, typically yielding very low ammonia (NH) production rates. In this study, we present a continuous flow plasma-electrochemical reactor system for the direct conversion of nitrogen from air into ammonia. In our system, nitrogen molecules are first converted into a mixture of NO species in the plasma reactor, which are then fed into an electrochemical reactor.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!