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La cola del bacteriófago φ29 posee un bucle formador de poros para la penetración de la membrana celular
Jingwei Xu1, Miao Gui1, Dianhong Wang1
1Centre for Infectious Diseases Research, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Beijing Advanced Innovation Center for Structural Biology, Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.
Nature
|June 17, 2016
Resumen
El bacteriófago φ29
Área de la Ciencia:
- Virología
- Biología estructural
- Microbiología
Sus antecedentes:
- La mayoría de los bacteriófagos poseen colas cruciales para la interacción de la célula huésped y la entrega de ADN.
- Los mecanismos de penetración de la membrana interna de la célula huésped por las colas de los bacteriófagos siguen sin estar claros.
Objetivo del estudio:
- Investigar la estructura y la función del producto genético del bacteriófago φ29 9 (gp9).
- Para aclarar el mecanismo de penetración de la membrana celular mediada por la cola de los bacteriófagos.
Principales métodos:
- Cristalografía de rayos X (resolución de 2,0 Å) del gp9.
- Pruebas bioquímicas.
- Análisis estructurales por microscopía electrónica.
- Comparaciones de secuencia y estructura con otras proteínas fagas.
Principales resultados:
- gp9 forma un tubo hexameric con bucles hidrofóbicos que bloquean la eyección de ADN.
- Tras la eyección de ADN, estos bucles forman un canal que abarca la bicapa lipídica.
- Este canal facilita la liberación del ADN genómico del bacteriófago, lo que indica un mecanismo de formación de poros.
Conclusiones:
- El bacteriófago φ29 utiliza un mecanismo de formación de poros para la penetración de la membrana celular, similar a algunos virus eucariotas.
- Los virus procariotas y eucariotas pueden compartir una evolución convergente para los mecanismos de ruptura de la membrana celular.
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