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In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
Published on: July 25, 2019
Bases estructurales para el ensamblaje y la activación del módulo SAGA histona H2B deubiquitinasa heterotetramérica
Alwin Köhler1, Erik Zimmerman, Maren Schneider
1Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany. alwin.koehler@mfpl.ac.at
Cell
|May 4, 2010
Resumen
El módulo SAGA de la enzima desubiquitinante (DUB) es el módulo SAGA.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
Sus antecedentes:
- Las enzimas desubiquitinantes (DUB) son reguladores cruciales de los procesos celulares.
- Los mecanismos específicos que controlan la actividad de DUB en diferentes entornos celulares no están completamente aclarados.
- El complejo SAGA recluta y activa la deubiquitinasa de levadura Ubp8.8.
Objetivo del estudio:
- Para determinar la estructura cristalina del módulo SAGA DUB completo.
- Para aclarar la base estructural para la activación y regulación de Ubp8 por sus socios no-sustrato.
- Comprender el papel de Sgf11 y Sgf73 en la desubiquitinación de la histona H2B.
Principales métodos:
- Cristalografía de rayos X para obtener la estructura del módulo SAGA DUB.
- Pruebas bioquímicas para analizar la función de los componentes del módulo DUB.
- Análisis funcional basado en la estructura.
Principales resultados:
- La estructura cristalina revela una arquitectura de dos lóbulos del módulo SAGA DUB, vinculado por Sgf73.
- Sus1 y Sgf11 interactúan con Ubp8 en lóbulos distintos, formando un "lóbulo de ensamblaje" y un "lóbulo catalítico".
- El dominio de dedo de zinc de Sgf11 está posicionado cerca del sitio activo de Ubp8, y Sgf73 actúa como un andamio.
Conclusiones:
- Sgf11 y Sgf73 juegan un papel esencial en la activación alostérica de Ubp8.8.
- La estructura del módulo SAGA DUB proporciona información sobre cómo los DUB son regulados por las proteínas que no son sustratos.
- Este estudio revela un mecanismo para la regulación alostérica de una enzima deubiquitinante por sus socios.
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