title: Nitrogenase activity of Herbaspirillum seropedicae grown under low iron levels requires the products of nifXorf1 genes.
abstract: Herbaspirillum seropedicae strains mutated in the nifX or orf1 genes showed 90% or 50% reduction in nitrogenase activity under low levels of iron or molybdenum respectively. Mutations in nifX or orf1 genes did not affect nif gene expression since a nifH::lacZ fusion was fully active in both mutants. nifX and the contiguous gene orf1 are essential for maximum nitrogen fixation under iron limitation and are probably involved in synthesis of nitrogenase iron or iron-molybdenum clusters.
authors.affiliation: Departamento de Patologia Básica, Universidade Federal do Paraná, CP 19046, 81531-990 Curitiba PR, Brazil. giseli@ufpr.br
authors.forename: Giseli
authors.initials: G
authors.lastname: Klassen
authors.forename: Fábio
authors.initials: F
authors.lastname: de Oliveira Pedrosa
authors.forename: Emanuel M
authors.initials: EM
authors.lastname: de Souza
authors.forename: M Geoffrey
authors.initials: MG
authors.lastname: Yates
authors.forename: Liu Un
authors.initials: LU
authors.lastname: Rigo
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020562:Betaproteobacteria / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005798:Genes, Bacterial; D007501:Iron / Q000378:metabolism*; D007763:Lac Operon; D008982:Molybdenum / Q000378:metabolism; D009586:Nitrogen Fixation / Q000235:genetics / Q000502:physiology*; D009591:Nitrogenase / Q000378:metabolism*; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins; C118795:NifX protein, Bacteria; D008982:Molybdenum; D007501:Iron; D009591:Nitrogenase