title: VnfY is required for full activity of the vanadium-containing dinitrogenase in Azotobacter vinelandii.
abstract: A gene from Azotobacter vinelandii whose product exhibits primary sequence similarity to the NifY, NafY, NifX, and VnfX family of proteins, and which is required for effective V-dependent diazotrophic growth, was identified. Because this gene is located downstream from vnfK in an arrangement similar to the relative organization of the nifK and nifY genes, it was designated vnfY. A mutant strain having an insertion mutation in vnfY has 10-fold less vnf dinitrogenase activity and exhibits a greatly diminished level of (49)V label incorporation into the V-dependent dinitrogenase when compared to the wild type. These results indicate that VnfY has a role in the maturation of the V-dependent dinitrogenase, with a specific role in the formation of the V-containing cofactor and/or its insertion into apodinitrogenase.
authors.affiliation: Department of Biochemistry and Center for the Study of Nitrogen Fixation, College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Carmen
authors.initials: C
authors.lastname: Rüttimann-Johnson
authors.forename: Luis M
authors.initials: LM
authors.lastname: Rubio
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Dean
authors.forename: Paul W
authors.initials: PW
authors.lastname: Ludden
mesh_terms: D000595:Amino Acid Sequence; D016948:Azotobacter vinelandii / Q000201:enzymology* / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017037:Dinitrogenase Reductase / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009591:Nitrogenase / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014639:Vanadium / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D017037:Dinitrogenase Reductase; C118795:NifX protein, Bacteria; C075094:NifY protein, Bacteria; D014639:Vanadium; D009591:Nitrogenase