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Estructura cristalina de un complejo GLI-ADN de cinco dedos: nuevas perspectivas sobre los dedos de zinc
1Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge 02139.
Science (New York, N.Y.)
|September 24, 1993
Resumen
La estructura cristalina de los dedos de zinc oncogénicos GLI humanos unidos al ADN revela patrones de unión únicos. Este hallazgo ofrece nuevos conocimientos sobre los mecanismos de reconocimiento del ADN del dedo de zinc.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
- Genética La genética.
Sus antecedentes:
- Las proteínas del dedo de zinc son proteínas cruciales que se unen al ADN.
- El factor de transcripción IIIA (TFIIIA) fue la primera proteína del dedo de zinc descubierta.
- El oncogén GLI es una importante familia de proteínas humanas.
Objetivo del estudio:
- Para determinar la estructura cristalina de los cinco dedos de zinc del oncogén GLI complejos con ADN.
- Para analizar las interacciones de unión y la conformación del ADN.
- Para comparar el reconocimiento de GLI-DNA con otras proteínas del dedo de zinc como Zif268.8.
Principales métodos:
- Cristalografía de rayos X con una resolución de 2.6 A.
- Análisis estructural del complejo proteína-ADN.
- Análisis comparativo con el complejo Zif268.
Principales resultados:
- Se determinó la estructura cristalina del complejo GLI-ADN.
- El dedo uno no entra en contacto con el ADN; los dedos dos a cinco se unen a la ranura mayor.
- Los dedos GLI exhiben una disposición no periódica, con los dedos cuatro y cinco haciendo contactos extensos con la base.
- La región de ADN unida por GLI tiene una conformación intermedia B-DNA/A-DNA.
Conclusiones:
- El mecanismo de reconocimiento de ADN del dedo de zinc de GLI difiere del complejo Zif268.
- El modo de unión único proporciona nuevas perspectivas sobre las interacciones entre el dedo de zinc y el ADN.
- Conocimientos estructurales sobre la función de la GLI en la oncogénesis.
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