Isolation of a glutamate synthase (GOGAT)-negative, pleiotropically N utilization-defective mutant of Azospirillum brasilense: cloning and partial characterization of GOGAT structural gene.
J Bacteriol
; 175(24): 8024-9, 1993 Dec.
Article
em En
| MEDLINE
| ID: mdl-7902833
An Azospirillum brasilense mutant (N12) pleiotropically defective in the assimilation of nitrogenous compounds (Asm-) was isolated and found lacking in the glutamate synthase (GOGAT-). The glt (GOGAT) locus of A. brasilense was identified by isolating a broad-host-range pLAFR1 cosmid clone from a gene library of the bacterium that rectified Asm- and GOGAT- defects (full recovery of activities of the nitrogenase, the assimilatory nitrate and nitrite reductases, and the glutamate synthase). A 7.5-kb EcoRI fragment of the cosmid clone that also complemented N12 was partially sequenced to identify the open reading frame for the alpha-subunit of GOGAT. The amino acid sequences deduced from the partial nucleotide sequences of the glt locus of A. brasilense showed considerable homology with that of the alpha-subunit of GOGAT coded by the gltB gene of Escherichia coli. The genetic lesion of N12 was found within the gltB gene of A. brasilense. The gltB promoter of A. brasilense showed the presence of a consensus sigma-70-like recognition site (as in E. coli) in addition to potential NtrA-RNA polymerase, IHF, and NifA binding sites.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Azospirillum brasilense
/
Genes Bacterianos
/
Glutamato Sintase
/
Mutação
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
J Bacteriol
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Índia
País de publicação:
Estados Unidos