Transcriptional regulation of a second flavodoxin gene from Klebsiella pneumoniae

Gene. 1997 Jul 31;194(2):235-40. doi: 10.1016/s0378-1119(97)00168-6.


A second flavodoxin gene, distinct from the nifF gene encoding nitrogenase flavodoxin, has been isolated from Klebsiella pneumoniae. This flavodoxin gene is a homologue of the E. coli fldA gene and is located 286 bp upstream of the K. pneumoniae fur gene. Primer extension analysis revealed an unusual promoter region upstream of the K. pneumoniae fldA gene that does not match the -35/-10 consensus sequence. Transcriptional analyses using a Fur titration assay and fldA gene fusions demonstrated that, unlike E. coli fldA, the K. pneumoniae fldA gene is not constitutively expressed. Rather, the fldA gene of K. pneumoniae is repressed in high iron conditions by the ferric uptake regulator (Fur) protein. Expression of K. pneumoniae fldA is also induced by heat shock but not by salt stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • DNA Primers
  • Flavodoxin / genetics*
  • Gene Expression Regulation, Bacterial*
  • Heat-Shock Response
  • Iron / metabolism
  • Klebsiella pneumoniae / genetics*
  • Klebsiella pneumoniae / metabolism
  • Peptide Chain Initiation, Translational
  • Sequence Analysis, DNA
  • Transcription, Genetic


  • DNA Primers
  • Flavodoxin
  • Iron