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La categorización del ARN guía permite la elección del sitio objetivo en los transposones Tn7-CRISPR-Cas
Michael T Petassi1, Shan-Chi Hsieh1, Joseph E Peters1
1Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
Cell
|December 3, 2020
Resumen
Los sistemas CRISPR-Cas en elementos similares a Tn7 utilizan ARN guía especializados para la transposición. Esto permite apuntar tanto a los plásmidos móviles como a los sitios cromosómicos, lo que permite una transferencia genética eficiente y la colonización del huésped.
Área de la Ciencia:
- Biología molecular
- Genética microbiana
- La genómica
Sus antecedentes:
- Los sistemas CRISPR-Cas son mecanismos inmunológicos adaptativos en las procariotas.
- Los transposones similares a Tn7 utilizan CRISPR-Cas para la integración de ADN dirigido.
- El prototipo Tn7 emplea vías distintas para la orientación cromosómica y plasmática.
Objetivo del estudio:
- Investigar los mecanismos de categorización del ARN guía (ARNg) en los elementos Tn7-CRISPR-Cas.
- Comprender cómo estos sistemas logran estrategias de doble orientación.
- Explorar el potencial de la ingeniería para mejorar la funcionalidad de CRISPR-Cas.
Principales métodos:
- Análisis comparativo de estructuras de ARNg y secuencias de reconocimiento.
- Ensayos funcionales para evaluar la eficacia de la transposición y la especificidad de la orientación.
- Análisis bioinformático de la adquisición y regulación del ARNg.
Principales resultados:
- Los elementos Tn7-CRISPR-Cas desarrollaron un sofisticado sistema de categorización de gRNA.
- Los distintos ARNg median la transposición a los plásmidos y los sitios de unión cromosómica.
- Los mecanismos incluyen la especialización de la secuencia, la tolerancia al desajuste y el reconocimiento regulado para evitar la auto-orientación.
Conclusiones:
- El estilo de vida de doble orientación de Tn7-CRISPR-Cas se basa en gRNA funcionalmente especializados y privatizados.
- Este sistema proporciona información sobre la evolución de la transposición y la cooptación de CRISPR-Cas.
- Los gRNA diseñados podrían mejorar las herramientas CRISPR-Cas para aplicaciones de edición de genoma.
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