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El replegamiento en la enzima permite la vigilancia del ARN pequeño y el ARN t por la enzima que agrega CCA
Claus-D Kuhn1, Jeremy E Wilusz2, Yuxuan Zheng3
1W.M. Keck Structural Biology Laboratory, Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.
Cell
|February 3, 2015
Resumen
La enzima de adición de CCA distingue entre ARN estables e inestables al detectar su respuesta a su acción mecánica. Los ARN estables son expulsados, mientras que los ARN inestables se someten a un segundo ciclo catalítico para la degradación.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- ARN Biología Biología ARN
- La bioquímica es la bioquímica.
Sus antecedentes:
- La transcripción eucariota genera ARN largos no codificantes (ARNlnc), incluidos MALAT1 y Menβ.
- Algunos lncRNAs producen pequeños ARN similares al tRNA junto con transcripciones maduras.
- La enzima que agrega CCA regula la estabilidad del tRNA y del ARN similar al tRNA.
Objetivo del estudio:
- Aclarar el mecanismo por el cual la enzima que agrega CCA diferencia entre ARN estables e inestables.
- Para entender cómo se procesan los ARN similares al tRNA y los ARN t de buena fe.
Principales métodos:
- Caracterización de la actividad de la enzima que agrega CCA en diferentes sustratos de ARN.
- Análisis del replegamiento del ARN y los ciclos catalíticos.
- Investigación de las interacciones enzima-ARN y las fuerzas mecánicas.
Principales resultados:
- La enzima de adición de CCA agrega una segunda repetición de CCA a los ARN inestables, iniciando la degradación.
- Los ARN estables y las transcripciones similares al tRNA se expulsan después de la adición inicial de CCA.
- La unión de nucleótidos inducida por enzimas desencadena un movimiento de tornillo, creando un par que diferencia los destinos del ARN.
Conclusiones:
- Los ARN autocomproban su estabilidad a través de respuestas diferenciales a la interrogación mecánica de la enzima que agrega CCA.
- La enzima que agrega CCA actúa como un vieso molecular, distinguiendo los sustratos de ARN en función de sus respuestas estructurales.
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