Characterization of a long overlooked copper protein from methane- and ammonia-oxidizing bacteria. Issue 1 (December 2018)

• Record Type: Journal Article
• Authors: Fisher, Oriana; Kenney, Grace; Ross, Matthew; Ro, Soo; Lemma, Betelehem; Batelu, Sharon; Thomas, Paul; Sosnowski, Victoria; DeHart, Caroline; Kelleher, Neil; Stemmler, Timothy; Hoffman, Brian; Rosenzweig, Amy
• Is Part Of: Nature communications. Volume 9:Issue 1(2018)
• Page Start: 1
• Page End: 12
• Publication Date: 2018-12
• Subjects: Biology -- Periodicals; Physical sciences -- Periodicals; 505
• DOI: 10.1038/s41467-018-06681-5
• Languages: English
• ISSNs: 2041-1723

Abstract

Abstract Methane-oxidizing microbes catalyze the oxidation of the greenhouse gas methane using the copper-dependent enzyme particulate methane monooxygenase (pMMO). Isolated pMMO exhibits lower activity than whole cells, however, suggesting that additional components may be required. A pMMO homolog, ammonia monooxygenase (AMO), converts ammonia to hydroxylamine in ammonia-oxidizing bacteria (AOB) which produce another potent greenhouse gas, nitrous oxide. Here we show that PmoD, a protein encoded within manypmo operons that is homologous to the AmoD proteins encoded within AOBamo operons, forms a copper center that exhibits the features of a well-defined CuA site using a previously unobserved ligand set derived from a cupredoxin homodimer. PmoD is critical for copper-dependent growth on methane, and genetic analyses strongly support a role directly related to pMMO and AMO. These findings identify a copper-binding protein that may represent a missing link in the function of enzymes critical to the global carbon and nitrogen cycles. Methane- and ammonia-oxidizing bacteria use the integral membrane, copper-dependent enzymes particulate methane monooxygenase (pMMO) and ammonia monooxygenase (AMO) to oxidize methane and ammonia. Here the authors structurally characterize the copper-binding protein PmoD, which contains an unusual CuA site and their genetic analyses strongly support a pMMO and AMO related function of PmoD.