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Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events
Published on: May 13, 2019
Conocimiento estructural de la síntesis de la translesión por ADN Pol II
1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Building 5, Room B1-03, Bethesda, MD 20892, USA.
Cell
|January 13, 2010
Resumen
La ADN polimerasa II (Pol II) de Escherichia coli y la eucariota Rev3 son polimerasas de la familia B que realizan la síntesis de la translesión. DNA Pol II utiliza características estructurales únicas, incluido el salto de plantillas, para eludir las lesiones del ADN y mantener la integridad genómica.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Genética La genética.
Sus antecedentes:
- Las polimerasas de la familia B, incluidos el ADN Pol II de E. coli y el Rev3 eucariótico, son cruciales para la reparación del ADN.
- Las polimerasas replicativas de alta fidelidad pueden ser ineficaces para replicar el ADN más allá de sitios dañados o no coincidentes.
- La síntesis de traslación (TLS) es un mecanismo empleado por polimerasas especializadas para eludir las lesiones del ADN.
Objetivo del estudio:
- Aclarar las propiedades bioquímicas y estructurales del ADN Pol II de E. coli que permiten la síntesis de la translesión.
- Comprender los mecanismos por los que el ADN Pol II evita las lesiones del ADN, incluido el salto de plantilla.
- Para investigar cómo el ADN Pol II equilibra la replicación eficiente del ADN no dañado con la capacidad de TLS.
Principales métodos:
- Análisis bioquímicos para caracterizar la actividad del ADN Pol II.
- Estudios estructurales para determinar la estructura tridimensional del ADN Pol II.
- Análisis de la partición del sustrato de ADN entre los sitios activos y exonucleasa.
Principales resultados:
- DNA Pol II puede extender los primers más allá de las lesiones directamente o a través del salto de plantilla, acomodando nucleótidos de plantilla en bucle en pequeñas cavidades.
- La capacidad de acomodar múltiples alternativas de salida de bucle complica los espectros de mutación de la síntesis de derivación.
- La partición alterada del sustrato de ADN entre el sitio activo y el sitio de la exonucleasa de corrección mejora TLS.
- Los cambios sutiles de aminoácidos alejados del sitio activo permiten que el ADN Pol II replique eficientemente el ADN normal mientras también realiza TLS.
Conclusiones:
- El ADN Pol II posee propiedades estructurales y bioquímicas únicas que facilitan una síntesis de traslación eficiente.
- El salto de plantillas y la partición alterada del sustrato son mecanismos clave que permiten al ADN Pol II eludir el daño del ADN.
- DNA Pol II representa una polimerasa especializada de la familia B capaz de replicar con alta fidelidad y tolerancia al daño.
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