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Abstract The Fe protein of nitrogenase plays multiple roles in substrate reduction and cluster maturation via its redox‐active [Fe4S4] cluster. Here we report the synthesis and characterization of a water‐soluble [Fe4Se4] cluster that is used to substitute the [Fe4S4] cluster of theAzotobacter vinelandiiFe protein (AvNifH). Biochemical, EPR and XAS/EXAFS analyses demonstrate the ability of the [Fe4Se4] cluster to adopt the super‐reduced, all‐ferrous state upon its incorporation intoAvNifH. Moreover, these studies reveal that the [Fe4Se4] cluster inAvNifH already assumes a partial all‐ferrous state ([Fe4Se4]0) in the presence of dithionite, where its [Fe4S4] counterpart inAvNifH exists solely in the reduced state ([Fe4S4]1+). Such a discrepancy in the redox properties of theAvNifH‐associated [Fe4Se4] and [Fe4S4] clusters can be used to distinguish the differential redox requirements for the substrate reduction and cluster maturation of nitrogenase, pointing to the utility of chalcogen‐substituted FeS clusters in future mechanistic studies of nitrogenase catalysis and assembly.
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Nitrogenase Fe Protein: A Multi-Tasking Player in Substrate Reduction and Metallocluster Assembly
The Fe protein of nitrogenase plays multiple roles in substrate reduction and metallocluster assembly. Best known for its function to transfer electrons to its catalytic partner during nitrogenase catalysis, the Fe protein is also a key player in the biosynthesis of the complex metalloclusters of nitrogenase. In addition, it can function as a reductase on its own and affect the ambient reduction of CO2 or CO to hydrocarbons. This review will provide an overview of the properties and functions of the Fe protein, highlighting the relevance of this unique FeS enzyme to areas related to the catalysis, biosynthesis, and applications of the fascinating nitrogenase system.
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- Award ID(s):
- 1651398
- PAR ID:
- 10466688
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Molecules
- Volume:
- 27
- Issue:
- 19
- ISSN:
- 1420-3049
- Page Range / eLocation ID:
- 6743
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/molecules27196743
