Nucleotide sequence of the gene encoding the nitrogenase iron protein (nifH) of Azospirillum brasilense and identification of a region controlling nifH transcription.
Mol Gen Genet
; 220(1): 81-7, 1989 Dec.
Article
em En
| MEDLINE
| ID: mdl-2608029
The DNA sequence was determined for the Azospirillum brasilense nifH gene and part of the nifD gene. The nifH gene is 885 bp long and encodes 293 amino acid residues. The region upstream of the nifH open reading frame contains a putative promoter whose sequence shows perfect homology with promoters of other diazotrophic bacteria and two putative upstream activator sequences. Experiments with the promoter-probe vector pAF300 showed that this region promotes transcription in response to the nitrogen and oxygen availability of the cell. The amino acid sequence was deduced from the DNA nucleotide sequence of nifH; the polypeptide contains the four cysteine residues highly conserved among other nifH products and an arginine residue at position 101 which could be the site of the modification occurring during the "switch-off" of nitrogenase. The codon usage appears to be very biased reflecting the high G + C content of the Azospirillum nifH gene. In a comparison of the amino acid sequence with the other 18 known nifH gene products, the A. brasilense nifH product showed the highest level of homology with fast-growing Rhizobia suggesting interesting evolutionary implications.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxirredutases
/
Transcrição Gênica
/
Azospirillum brasilense
/
Genes Bacterianos
/
Fixação de Nitrogênio
/
Nitrogenase
Tipo de estudo:
Diagnostic_studies
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Mol Gen Genet
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
Itália
País de publicação:
Alemanha