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Promoter Capture Hi-C: High-resolution, Genome-wide Profiling of Promoter Interactions
Published on: June 28, 2018
Conocimientos estructurales sobre la actividad de las proteínas de unión al potenciador
Mathieu Rappas1, Jorg Schumacher, Fabienne Beuron
1Department of Biological Sciences, Imperial College London, London, SW7 2AZ, UK.
Science (New York, N.Y.)
|March 26, 2005
Resumen
Los activadores de la sigma54-ARN polimerasa utilizan la hidrólisis de ATP para activar la transcripción. Este estudio revela cómo PspF ((1-275) se une a sigma54 a través de cambios conformacionales dependientes de nucleótidos, identificados mediante el uso de cryo-EM.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología Estructural Biología Estructural
- La bioquímica es la bioquímica.
Sus antecedentes:
- La holoenzima de la polimerasa sigma54-ARN controla el inicio de la transcripción bacteriana.
- Las proteínas activadoras son esenciales para la transcripción sigma54-dependiente, utilizando la hidrólisis de ATP.
- La proteína de choque fagal F [PspF(1-275) ] es un activador clave de sigma54.
Objetivo del estudio:
- Para aclarar el mecanismo estructural de la interacción de PspF ((1-275) con sigma54.
- Para entender el papel de la hidrólisis del ATP en la formación del complejo activador-sigma54.
- Para determinar la estructura del complejo activador-sigma54 a una resolución casi atómica.
Principales métodos:
- Microscopía electrónica criogénica (cryo-EM) para determinar la estructura de PspF ((1-275) unido a sigma54.
- Ajuste de una estructura cristalina de alta resolución de PspF ((1-275) en el mapa de cryo-EM.
- Análisis mutacional y comparación de dominios de unión al potenciador en diferentes estados de nucleótidos.
Principales resultados:
- Se obtuvo una estructura cryo-EM de resolución de 20 angstroms del complejo PspF ((1-275) -sigma54).
- Se identificaron dos bucles específicos dentro de PspF ((1-275) como cruciales para la unión sigma54.
- Se propusieron cambios conformacionales dependientes de nucleótidos en PspF ((1-275) para facilitar la asociación sigma54.
Conclusiones:
- El estudio proporciona una base estructural para la comprensión de la función del activador sigma54.
- La flexibilidad conformal impulsada por la unión y la hidrólisis de ATP es crítica para la interacción activador-sigma54.
- Este trabajo hace avanzar el conocimiento de los mecanismos de regulación de la transcripción bacteriana.
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