Repression of the E. coli lactose operon by cooperation between two individually unproductive "half-operator" sites.
C R Acad Sci III
; 315(11): 403-7, 1992.
Article
em En
| MEDLINE
| ID: mdl-1292855
ABSTRACT
Two remote and weak lac regressor binding sites can be used jointly to repress the synthesis of beta-galactosidase in E. coli, while they cannot separately. When this result is discussed in reference to the various modes of cooperation between the sites, it supports with a new approach a model implying the simultaneous binding of lac repressor to both sites with the formation of a DNA loop. In connection with this point, we present a new strategy to detect cooperative interactions in vivo, based on the asymmetry of the DNA binding site, formally equivalent here to a half-site, heterodimerization of the protein, and influence of orientation of the sites on repression at short and long distance.
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Base de dados:
MEDLINE
Assunto principal:
DNA Bacteriano
/
Regiões Operadoras Genéticas
/
Escherichia coli
/
Óperon Lac
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
C R Acad Sci III
Assunto da revista:
BIOLOGIA
Ano de publicação:
1992
Tipo de documento:
Article