title: Fnr is involved in oxygen control of Herbaspirillum seropedicae N-truncated NifA protein activity in Escherichia coli.
abstract: Herbaspirillum seropedicae is an endophytic diazotroph belonging to the beta-subclass of the class Proteobacteria, which colonizes many members of the Gramineae. The activity of the NifA protein, a transcriptional activator of nif genes in H. seropedicae, is controlled by ammonium ions through its N-terminal domain and by oxygen through mechanisms that are not well understood. Here we report that the NifA protein of H. seropedicae is inactive and more susceptible to degradation in an fnr Escherichia coli background. Both effects correlate with oxygen exposure and iron deprivation. Our results suggest that the oxygen sensitivity and iron requirement for H. seropedicae NifA activity involve the Fnr protein.
authors.affiliation: Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, CP 19046, Curitiba, PR 81531-990, Brazil.
authors.forename: Rose A
authors.initials: RA
authors.lastname: Monteiro
authors.forename: Emanuel M
authors.initials: EM
authors.lastname: de Souza
authors.forename: M Geoffrey
authors.initials: MG
authors.lastname: Yates
authors.forename: Fabio O
authors.initials: FO
authors.lastname: Pedrosa
authors.forename: Leda S
authors.initials: LS
authors.lastname: Chubatsu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020562:Betaproteobacteria / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; C061338:NifA protein, Bacteria; D014157:Transcription Factors; D007501:Iron; D010100:Oxygen