Document Type
Article
Publication Date
12-13-2023
Abstract
Nitrogenase is the only enzyme that catalyzes the reduction of nitrogen gas into ammonia. Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Many nitrogen fixing bacteria protect nitrogenase from CO inhibition using the protective protein CowN. This work demonstrates that a conserved glutamic acid residue near the C-terminus of Gluconacetobacter diazotrophicus CowN is necessary for its function. Mutation of the glutamic acid residue abolishes both CowN’s protection against CO inhibition and the ability of CowN to bind to nitrogenase. In contrast, a conserved C-terminal cysteine residue is not important for CO protection by CowN. Overall, this work uncovers structural features in CowN that are required for its function and provides new insights into its nitrogenase binding and CO protection mechanism.
Recommended Citation
Willard, D. L.; Arellano, J. J.; Underdahl, M.; Lee, T. M.; Ramswamy, A. S.; Fumes, G.; Kliman, A.; Wong, E. Y.; Owens, C. P. Mutational Analysis of the Nitrogenase Carbon Monoxide Protective Protein CowN Reveals That a Conserved C-Terminal Glutamic Acid Residue Is Necessary for Its Activity. Biochemistry 2024, 63, 152–158. https://doi.org/10.1021/acs.biochem.3c00421
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This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
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Comments
This article was originally published in Biochemistry, volume 63, issue 1, in 2024. https://doi.org/10.1021/acs.biochem.3c00421