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Published on: April 26, 2013
Estructura del dominio de unión al ADN del zinc GAL4
P J Kraulis1, A R Raine, P L Gadhavi
1Department of Biochemistry, University of Cambridge, UK.
Nature
|April 2, 1992
Resumen
La proteína GAL4 es la proteína GAL4.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
- Genética La genética.
Sus antecedentes:
- El activador transcripcional de la levadura GAL4 regula la transcripción de los genes GAL1 y GAL10.
- GAL4 contiene un dominio de unión al ADN conservado rico en cisteína que se une al zinc.
- Anteriormente se planteó la hipótesis de que la estructura de este dominio se parecía a los dedos de zinc TFIIIA.
Objetivo del estudio:
- Para determinar la estructura de la solución del dominio de unión al ADN GAL4.
- Para aclarar la base estructural de la unión al ADN de GAL4 y la activación de la transcripción.
- Para comparar la estructura del dominio de unión al zinc de GAL4 con el dedo de zinc conocido y los dominios de unión al ADN del receptor.
Principales métodos:
- 1H-113Cd espectroscopia bidimensional de resonancia magnética nuclear (2D NMR) del dominio unido al cadmio.
- Análisis de los motivos estructurales de la proteína y grupo de coordinación de metales.
- Comparación con los datos estructurales existentes para otras proteínas de unión al ADN.
Principales resultados:
- El dominio de unión al ADN GAL4 adopta una nueva estructura pseudo-simétrica.
- Dos motivos de hélice giratoria se empaquetan alrededor de un grupo de Zn2Cys6.
- Esta estructura difiere significativamente de los dedos de zinc de tipo TFIIIA y los dominios de unión al ADN de los receptores de hormonas esteroideas.
Conclusiones:
- El dominio de unión de zinc GAL4 posee un pliegue estructural único.
- Esta estructura distinta subyace en sus funciones específicas de regulación de la unión al ADN y de la transcripción.
- Los hallazgos amplían la diversidad estructural conocida de los dominios de unión al zinc en los activadores transcripcionales.
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