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Publication Abstract from PubMed

Ammonia oxidizing archaea (AOA) are among the most abundant microorganisms on earth and are known to be a major source of nitrous oxide (N(2)O) emissions, although biochemical origins of this N(2)O remain unknown. Enzymological details of AOA nitrogen metabolism are broadly unavailable. We report the recombinant expression, purification, and characterization of a multicopper oxidase, Nmar_1354, from the AOA Nitrosopumilus maritimus. We show that Nmar_1354 selectively produces nitroxyl (HNO) by coupling the oxidation of the obligate nitrification intermediate hydroxylamine (NH(2)OH) to dioxygen (O(2)) reduction. This HNO undergoes several downstream reactions, although the major fates are production of N(2) via reaction with NH(2)OH and dimerization with itself to yield N(2)O. These results afford one plausible enzymatic origin for N(2)O release by AOA. Moreover, these results reveal a physiologically relevant enzymatic reaction for producing HNO, an enigmatic nitrogen oxide speculated to be operative in cellular signaling and in energy transduction.

Nitrous oxide production via enzymatic nitroxyl from the nitrifying archaeon Nitrosopumilus maritimus.,Voland RW, Wang H, Abruna HD, Lancaster KM Proc Natl Acad Sci U S A. 2025 Jan 21;122(3):e2416971122. doi: , 10.1073/pnas.2416971122. Epub 2025 Jan 17. PMID:39823305^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.