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Estructura cristalina de un fragmento de subunidad sigma 70 de la ARN polimerasa de E. coli

A Malhotra¹, E Severinova, S A Darst

¹Rockefeller University, New York, New York 10021, USA.

|October 4, 1996

Resumen

La estructura cristalina de un fragmento de subunidad sigma 70 revela cómo se une a la ARN polimerasa e interactúa con el ADN promotor. Esto proporciona información sobre la regulación de la unión al ADN y los mecanismos de fusión de promotores.

Área de la Ciencia:

Biología Molecular Biología Molecular
Biología Estructural Biología estructural.
La bioquímica es la bioquímica.

Sus antecedentes:

La subunidad sigma 70 es crucial para el reconocimiento del promotor de polimerasa de ARN bacteriano.
Comprender su relación estructura-función es clave para descifrar la iniciación de la transcripción.

Objetivo del estudio:

Para determinar la estructura cristalina de un fragmento clave de la subunidad de especificidad del promotor de E. coli sigma 70.
Para dilucidar la base estructural para la unión de la ARN polimerasa del núcleo y la interacción del ADN promotor.

Principales métodos:

Cristalografía de rayos X con una resolución de 2.6 A.
Análisis estructural del fragmento de la subunidad sigma 70.

Principales resultados:

Se identificaron caras distintas para la unión de la ARN polimerasa del núcleo y la interacción del ADN promotor.
Residuos aromáticos caracterizados involucrados en la fusión del promotor en el elemento -10.
Propuso un mecanismo para inhibir las interacciones del ADN en ausencia de ARN polimerasa.

Conclusiones:

La estructura determinada proporciona un marco para la comprensión de la función sigma 70.
Ofrece información sobre la regulación de la unión al ADN y la fusión del promotor.
Facilita la interpretación de los datos genéticos y bioquímicos relacionados con la iniciación de la transcripción.

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