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Analysis of Termination of Transcription Using BrUTP-strand-specific Transcription Run-on (TRO) Approach
Published on: March 12, 2017
El enlace de la proteína de terminación de la transcripción con el ARN naciente y el ADN de la plantilla
1Department of Biochemistry and Molecular Biophysics and Institute of Cancer Research, Columbia University, New York, NY 10032, USA.
Science (New York, N.Y.)
|December 22, 1999
Resumen
Coliphage HK022 La proteína Nun se une a las transcripciones nacientes e interactúa con la ARN polimerasa para bloquear la transcripción. Nun detiene la transcripción mediante el anclaje de la ARN polimerasa al ADN, un mecanismo estudiado mediante el enlace cruzado.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Virología Virología.
- La bioquímica es la bioquímica.
Sus antecedentes:
- La proteína Coliphage HK022 Nun regula la transcripción.
- El motivo amino-terminal de Nun se une al ARN naciente, mientras que su dominio carboxilo-terminal interactúa con la ARN polimerasa (RNAP).
- La interacción de RNAP por Nun inhibe la elongación de la transcripción.
Objetivo del estudio:
- Para investigar las interacciones moleculares de la terminación carboxilo de Nun.
- Para aclarar el mecanismo por el cual Nun detiene el alargamiento de la transcripción.
- Comprender el papel del zinc (Zn2+) y de la E. coli NusA en la unión del ARN de Nun.
Principales métodos:
- Modificación química del extremo carboxilo de Nun con un enlace cruzado.
- Estudiar las interacciones entre Nun, la ARN polimerasa y el ADN mediante el enlace cruzado.
- Investigando los efectos del zinc y NusA en las interacciones Nun-RNA.
Principales resultados:
- El extremo carboxilo de Nun entra en contacto con E. coli NusA.
- Se observaron contactos intramoleculares dependientes de Zn2+ dentro del extremo carboxílico de Nun.
- Nun enlazado a la plantilla de ADN en complejos de alargamiento de transcripción en pausa.
- Nun detiene la transcripción mediante el anclaje de RNAP al ADN.
Conclusiones:
- Nun utiliza su extremo carboxilo para interactuar con NusA y formar contactos intramoleculares.
- Nun detiene la transcripción mediante el anclaje físico de RNAP a la plantilla de ADN.
- Estos hallazgos proporcionan información sobre los mecanismos de regulación de la transcripción entre fagos y huéspedes.
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