Cell
Volume 63, Issue 1, 5 October 1990, Pages 11-22
Journal home page for Cell

Article
The integration host factor stimulates interaction of RNA polymerase with NIFA, the transcriptional activator for nitrogen fixation operons

https://doi.org/10.1016/0092-8674(90)90284-LGet rights and content

Abstract

The regulatory protein NIFA activates transcription of nitrogen fixation (nif) operons by the σ54 holoenzyme form of RNA polymerase. NIFA from Klebsiella pneumoniae activates transcription from the nifH promoter in vitro; in addition, the integration host factor, IHF, binds between the nifH promoter and an upstream binding site for NIFA. We demonstrate here that IHF greatly stimulates NIFA-mediated activation of nifH transcription in vitro and thus that the two factors are functionally synergistic. Electron micrographs indicate that IHF bends the DNA in the nifH promoter regulatory region. Although IHF binds close to the nifH promoter, it does not directly stlmulate binding of σ54 holoenzyme. Rather, the IHF-induced bend may facilitate productive contacts between NIFA and σ54 holoenzyme that lead to the formation of open complexes. IHF binds to nif promoter regulatory regions from a variety of organisms within the phylum “purple bacteria,” suggesting a general ability to stimulate NIFA-mediated activation of nif transcription.

References (76)

  • A. Maxam et al.

    Sequencing end-labelled DNA with base-specific chemical cleavages

    Meth. Enzymol.

    (1980)
  • E. Morett et al.

    In vivo studies on the interaction of RNA polymerase-σ54 with the Klebsiella pneumoniae and Rhizobium meliloti nifH promoters: the role of NIFA in the formation of an open promoter complex

    J. Mol. Biol.

    (1989)
  • H.A. Nash et al.

    Purification and properties of the Escherichia coli protein factor required for λ integrative recombination

    J. Biol. Chem.

    (1981)
  • I.-M. Pretorius et al.

    Identification and cloning of Thlobacilius ferrooxidans structural nif genes in Escherichia coli

    Gene

    (1986)
  • C.A. Robertson et al.

    Bending of the bacteriophage lambda attachment site by Escherlchia coli integration host factor

    J. Biol. Chem.

    (1988)
  • T.T. Stenzel et al.

    The integration host factor of Escherichia coli binds to bent DNA at the origin of replication of the plasmid pSC101

    Cell

    (1987)
  • F.W. Studier et al.

    Use of bacteriophage T7 RNA polymerase to direct selective high-level expression of cloned genes

    J. Mol. Biol.

    (1986)
  • M.-L. Vignais et al.

    Asymmetric DNA bending induced by the yeast multifunctional factor TUF

    J. Biol. Chem.

    (1989)
  • C.-C. Yang et al.

    The Interaction of E. coli IHF protein with its specific binding sites

    Cell

    (1989)
  • O.M. Aguilar et al.

    Rhizobium mellioti nifN (fixF) gene is part of an operon regulated by a nifA-dependent promoter and codes for a polypeptide homologous to the nifK gene product

    J. Bacteriol.

    (1987)
  • A. Alvarez-Morales et al.

    Expression of Rhizobium japonicum nifH and nifDK operons can be activated by the Klebsialla pneumonise nifA protein but not by the product of ntrC

    Mol. Gen. Genet.

    (1985)
  • A. Alvarez-Morales et al.

    Activation of the Bradyrhizobium japonicum nifH and nifDK operons is dependent on promoter-upstream DNA sequences

    Nucl. Acids Res.

    (1986)
  • S.W. Artz et al.

    Histidine regulation in Salmonella typhimurium: an activator attenuator model of gene regulation

  • M. Better et al.

    Deletion analysis of Rhizoblum meliloti symbiotic promoters

    EMBO J.

    (1985)
  • M. Buck et al.

    Mutations in the RNA polymerase recognition sequence of the Klebslelle pneumoniae nifH promoter permitting transcriptional activation in the absence of NifA binding to upstream activator sequences

    Nucl. Acids Res.

    (1989)
  • M. Buck et al.

    Upstream activator sequences are present in the promoters of nitrogen fixation genes

    Nature

    (1986)
  • W.J. Buikema et al.

    Conservation of structure and location of Rhizobium meliloti and Klebslella pneumoniae nifB genes

    J. Bacteriol.

    (1987)
  • M. Comb et al.

    Proteins bound at adjacent DNA elements act synergistically to regulate human proenkephalin cAMP inducible transcription

    EMBO J.

    (1988)
  • S. Ebeling et al.

    Mepping and nucleotide sequence of the nifS promoter of Bradyrhizobium japonicum

    Nucl. Acids Res.

    (1987)
  • D. Galas et al.

    A simple method for the detection of protein-DNA binding specificity

    Nucl. Acids Res.

    (1978)
  • S.C. Goodman et al.

    Functional replacement of a protein-induced bend in a DNA recombination site

    Nature

    (1989)
  • S. Goodman et al.

    Bending of DNA by IHF protein

  • P. Groeger et al.

    Organization and partial sequence of a DNA region of the Rhizobium leguminosarum symbiotic plasmid pRL6JI containing the genes fixABC, nifA, nifB and a novel open reading frame

    Nucl. Acids Res.

    (1987)
  • G.N. Gussin et al.

    Regulation of nitrogen fixation genes

    Annu. Rev. Genet.

    (1986)
  • H. Hennecke et al.

    Temperature control of nitrogen fixation in Klebsiella pneumoniee

    Arch. Microbiol.

    (1979)
  • S. Hill et al.

    Nitrogen fixation gene (nifL) involved in oxygen regulation of nitrogenase synthesis in Klebsiella pneumoniae

    Nature

    (1981)
  • J. Hirschman et al.

    Products of nitrogen regulatory genes ntrA and ntrC of enteric bacteria activate ginA transcription in vitro: evldence that the ntrA product is a σ factor

  • M.R. Jacobson et al.

    Physical and genetic map of the major nif gene cluster from Azotobacer vinelandil

    J. Bacteriol

    (1989)
  • Cited by (0)

    View full text