Model-building of Fnr and FixK DNA-binding domains suggests a basis for specific DNA recognition.
J Mol Recognit
; 2(3): 114-21, 1989 Nov.
Article
em En
| MEDLINE
| ID: mdl-2561529
ABSTRACT
The DNA-binding C-terminal domains of the regulatory proteins Fnr from Escherichia coli and FixK from Rhizobium meliloti have been modelled on the basis of their homologies to the CAP protein from E. coli. Residues Glu181, Thr182 and Arg185 of CAP, which are exposed residues of the DNA-recognition helix alpha F, are conserved in Fnr and FixK. However, Arg180 and Gly184 are substituted by Val and Ser respectively in Fnr. We propose that this valine makes a Van der Waals' contact with the first thymine in the Fnr consensus TTGA-N6-TCAA, and that the serine contributes to the binding by displacing a thymine-bound water molecule. The corresponding residues in FixK, Ile and Ser allow the same interactions with a thymine. Therefore we predict that FixK may recognize the same sites as Fnr. This is supported experimentally by showing that Fnr can substitute for FixK in activating the fixN gene in E. coli.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Contexto em Saúde:
3_ND
Problema de saúde:
3_neglected_diseases
/
3_zoonosis
Assunto principal:
Rhizobium
/
DNA Bacteriano
/
Modelos Moleculares
/
Proteínas de Ligação a DNA
/
Escherichia coli
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Mol Recognit
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
França