title: Extending the carbon chain: hydrocarbon formation catalyzed by vanadium/molybdenum nitrogenases.
abstract: In a small-scale reaction, vanadium-dependent nitrogenase has previously been shown to catalyze reductive catenation of carbon monoxide (CO) to ethylene, ethane, propylene, and propane. Here, we report the identification of additional hydrocarbon products [α-butylene, n-butane, and methane (CH(4))] in a scaled-up reaction featuring 20 milligrams of vanadium-iron protein, the catalytic component of vanadium nitrogenase. Additionally, we show that the more common molybdenum-dependent nitrogenase can generate the same hydrocarbons from CO, although CH(4) was not detected. The identification of CO as a substrate for both molybdenum- and vanadium-nitrogenases strengthens the hypothesis that CO reduction is an evolutionary relic of the function of the nitrogenase family. Moreover, the comparison between the CO-reducing capacities of the two nitrogenases suggests that the identity of heterometal at the active cofactor site affects the efficiency and product distribution of this reaction.
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA. yilinh@uci.edu
authors.forename: Yilin
authors.initials: Y
authors.lastname: Hu
authors.forename: Chi Chung
authors.initials: CC
authors.lastname: Lee
authors.forename: Markus W
authors.initials: MW
authors.lastname: Ribbe
mesh_terms: D016948:Azotobacter vinelandii; D055162:Biocatalysis; D002248:Carbon Monoxide / Q000378:metabolism*; D003903:Deuterium; D005030:Ethylenes / Q000378:metabolism; D006838:Hydrocarbons / Q000378:metabolism*; D008697:Methane / Q000378:metabolism; D008982:Molybdenum; D009591:Nitrogenase / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D013379:Substrate Specificity; D014639:Vanadium
chemical_list: D005030:Ethylenes; D006838:Hydrocarbons; D014639:Vanadium; D002248:Carbon Monoxide; D008982:Molybdenum; C036216:ethylene; D003903:Deuterium; D009591:Nitrogenase; D008697:Methane