title: Expression of a functional oxygen-labile nitrogenase component in the mitochondrial matrix of aerobically grown yeast.
abstract: The extreme sensitivity of nitrogenase towards oxygen stands as a major barrier to engineer biological nitrogen fixation into cereal crops by direct nif gene transfer. Here, we use yeast as a model of eukaryotic cell and show that aerobically grown cells express active nitrogenase Fe protein when the NifH polypeptide is targeted to the mitochondrial matrix together with the NifM maturase. Co-expression of NifH and NifM with Nif-specific Fe-S cluster biosynthetic proteins NifU and NifS is not required for Fe protein activity, demonstrating NifH ability to incorporate endogenous mitochondrial Fe-S clusters. In contrast, expression of active Fe protein in the cytosol requires both anoxic growth conditions and co-expression of NifH and NifM with NifU and NifS. Our results show the convenience of using mitochondria to host nitrogenase components, thus providing instrumental technology for the grand challenge of engineering N2-fixing cereals.
authors.forename: Gema
authors.initials: G
authors.lastname: López-Torrejón
authors.forename: Emilio
authors.initials: E
authors.lastname: Jiménez-Vicente
authors.forename: José María
authors.initials: JM
authors.lastname: Buesa
authors.affiliation: Department of Biochemistry, Midwestern University, Glendale, Arizona 85308, USA.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Hernandez
authors.forename: Hemant K
authors.initials: HK
authors.lastname: Verma
authors.forename: Luis M
authors.initials: LM
authors.lastname: Rubio
mesh_terms: D000332:Aerobiosis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D060846:Cell Engineering / Q000379:methods; D015870:Gene Expression; D007506:Iron-Sulfur Proteins / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D009586:Nitrogen Fixation / Q000235:genetics; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D019076:Transgenes
chemical_list: D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; C088637:NifU protein, Bacteria; C080001:nifS protein, Bacteria; D010088:Oxidoreductases; C029130:nitrogenase reductase; D010100:Oxygen