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Cited by 25Metalloenzymes and iron-sulfur proteinsEnzyme Structure and FunctionAmmonia Synthesis and Nitrogen Reduction

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Architecture of the RNF1 complex that drives biological nitrogen fixation

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Zhang, Lin, Einsle, Oliver·2024·Nature Chemical Biology
DOI 10.1038/s41589-024-01641-1

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Abstract

Biological nitrogen fixation requires substantial metabolic energy in form of ATP as well as low-potential electrons that must derive from central metabolism. During aerobic growth, the free-living soil diazotroph Azotobacter vinelandii transfers electrons from the key metabolite NADH to the low-potential ferredoxin FdxA that serves as a direct electron donor to the dinitrogenase reductases. This process is mediated by the RNF complex that exploits the proton motive force over the cytoplasmic membrane to lower the midpoint potential of the transferred electron. Here we report the cryogenic electron microscopy structure of the nitrogenase-associated RNF complex of A. vinelandii, a seven-subunit membrane protein assembly that contains four flavin cofactors and six iron-sulfur centers. Its function requires the strict coupling of electron and proton transfer but also involves major conformational changes within the assembly that can be traced with a combination of electron microscopy and modeling.

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Metadata

Authors
Zhang, L., & Einsle, O.
Affiliations
University of Freiburg (DE)
Corresponding author
Einsle, Oliver
ORCID
Venue
Nature Chemical Biology
Publisher
Springer Science and Business Media LLC
Published
2024-06-18
Volume
20
Issue
8
Pages
1078-1085
ISSN
  • 1552-4450 (ISSN-L)
  • 1552-4469
DOI
10.1038/s41589-024-01641-1
OpenAlex
W4399781533
Cited by
25
References
2
Citations by year
2026: 5 · 2025: 8 · 2024: 8
FWCI
1.40
Type
journal article
Language
en
Open access
Licence
Locations
  • Nature Chemical Biology (publishedVersion)
  • bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion, cc-by-nc-nd)
  • PubMed (publishedVersion)
Funders
  • Deutsche Forschungsgemeinschaft (278002225, RTG 2202, 192904750, INST 35, 46710898, CRC1381, 403222702)
  • Albert-Ludwigs-Universität Freiburg
  • Université de Fribourg
  • FP7 Ideas: European Research Council (310656)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Biochemistry › Metalloenzymes and iron-sulfur proteins
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Structural Biology › Enzyme Structure and Function
  • Physical Sciences › Chemical Engineering › Catalysis › Ammonia Synthesis and Nitrogen Reduction
Keywords
nitrogen fixation, Azotobacter vinelandii, NADH, electron transfer, proton motive force, flavin cofactor, iron-sulfur clusters, conformational change, dinitrogenase reductase
MeSH terms
Bacterial Proteins, Models, Molecular, Nitrogen Fixation, Oxidoreductases, Protein Conformation, Azotobacter vinelandii, Cryoelectron Microscopy

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