Structural basis for promoter-10 element recognition by the bacterial RNA polymerase σ subunit.
Cell
; 147(6): 1257-69, 2011 Dec 09.
Article
em En
| MEDLINE
| ID: mdl-22136875
ABSTRACT
The key step in bacterial promoter opening is recognition of the -10 promoter element (T(-12)A(-11)T(-10)A(-9)A(-8)T(-7) consensus sequence) by the RNA polymerase σ subunit. We determined crystal structures of σ domain 2 bound to single-stranded DNA bearing-10 element sequences. Extensive interactions occur between the protein and the DNA backbone of every -10 element nucleotide. Base-specific interactions occur primarily with A(-11) and T(-7), which are flipped out of the single-stranded DNA base stack and buried deep in protein pockets. The structures, along with biochemical data, support a model where the recognition of the -10 element sequence drives initial promoter opening as the bases of the nontemplate strand are extruded from the DNA double-helix and captured by σ. These results provide a detailed structural basis for the critical roles of A(-11) and T(-7) in promoter melting and reveal important insights into the initiation of transcription bubble formation.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fator sigma
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Thermus
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Proteínas de Bactérias
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DNA de Cadeia Simples
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Regiões Promotoras Genéticas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article