Quality and position of the three lac operators of E. coli define efficiency of repression.
EMBO J
; 13(14): 3348-55, 1994 Jul 15.
Article
em En
| MEDLINE
| ID: mdl-8045263
ABSTRACT
Repression of the lac promoter may be achieved in two different ways either by interference with the action of RNA polymerase or by interference with CAP activation. We investigated cooperative repression of the Escherichia coli lac operon by systematic conversion of its three natural operators (O1, O2 and O3) on the chromosome. We find that cooperative repression by tetrameric Lac repressor increases with both quality and proximity of the interacting operators. A short distance of 92 bp allows effective repression by two very weak operators (O3, O3). The cooperativity of lac operators is discussed in terms of a local increase of repressor concentration. This increase in concentration depends on flexible DNA which allows loop formation.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas Repressoras
/
Repressão Enzimática
/
Regiões Operadoras Genéticas
/
Escherichia coli
/
Óperon Lac
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
EMBO J
Ano de publicação:
1994
Tipo de documento:
Article
País de afiliação:
Alemanha