Control of nifH transcription in Azospirillum brasilense: involvement of NifA and of cis-acting sequences.
The regulatory sequences of Azospirillum brasilense Sp7 nifH gene were fused with the cam reporter gene and used for studying the factors controlling nifH transcription. A DNA sequence, downstream the ATG codon of nifH, that could be involved in the negative regulation of nifH transcription, was identified. The effect of 1 and 2 mM of ammonium on the transcription of the A. brasilense nifH gene and on the nitrogenase activity, in the presence of the Klebsiella pneumoniae NifA protein, was examined.
Fancelli
S
S
Dipartimento di Biologia Animale e Genetica, Università di Firenze, Florence, Italy.
Fani
R
R
Grifoni
A
A
Mugnai
M
M
Pastorelli
R
R
Bazzicalupo
M
M
D015806:Azospirillum brasilense / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology*; D003227:Conjugation, Genetic; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D007711:Klebsiella pneumoniae / Q000235:genetics; D009586:Nitrogen Fixation / Q000235:genetics*; D009591:Nitrogenase / Q000032:analysis; D010088:Oxidoreductases; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic / Q000235:genetics*; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; C061338:NifA protein, Bacteria; D014157:Transcription Factors; D010088:Oxidoreductases; D009591:Nitrogenase; C029130:nitrogenase reductase