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Detección de los intermediarios plegables de una proteína a medida que pasa a través del canal de translocación
Hiroshi Kadokura1, Jon Beckwith
1Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA. hkadokura@bs.naist.jp
Cell
|September 22, 2009
Resumen
Este estudio identifica los intermediarios de plegamiento de proteínas bacterianas, revelando cómo el modo de translocación afecta el plegamiento periplásmico. La actividad del ribosoma puede modular el plegamiento de proteínas incluso fuera de la célula.
Área de la Ciencia:
- El plegamiento de proteínas bacterianas.
- Biología molecular La biología molecular.
- Biología celular y de membrana.
Sus antecedentes:
- La mayoría de las proteínas exportadas bacterianas cruzan la membrana citoplasmática desplegada.
- La detección de los intermediarios de plegamiento de proteínas durante la translocación es un reto.
Objetivo del estudio:
- Para identificar los intermediarios de plegado cotranslacional y posttranslacional de una proteína periplásmica.
- Para entender cómo el modo de translocación influye en el plegamiento de proteínas en el periplasma.
Principales métodos:
- Identificación de productos intermedios de disulfuro mezclado entre una proteína periplásmica y DsbA.
- Análisis de la formación y resolución de enlaces disulfuro durante el plegamiento de las proteínas.
Principales resultados:
- Los intermediarios plegables cotranslacionales implican un enlace covalente transitorio con DsbA.
- Dos cisteínas que forman un disulfuro estructural pueden tener roles distintos en el plegamiento.
- La translocación cotranslacional vs. posttranslacional impacta en el plegamiento de las proteínas periplásmicas.
Conclusiones:
- El plegamiento de las proteínas en el periplasma está influenciado por el modo de translocación.
- La actividad de los ribosomas puede modular el plegamiento de proteínas en los compartimentos extracitosólicos.
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