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La estructura cristalina de la tirosina fosfatasa SHP-2 se encuentra
P Hof1, S Pluskey, S Dhe-Paganon
1Joslin Diabetes Center and the Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215, USA.
Cell
|March 10, 1998
Resumen
La SHP-2 es una tirosina fosfatasa.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Enzimología Enzimología.
Sus antecedentes:
- SHP-2 es una proteína tirosina fosfatasa crucial para la señalización celular.
- Su actividad está estrictamente regulada para controlar los procesos biológicos aguas abajo.
Objetivo del estudio:
- Para aclarar la base estructural de la regulación de la actividad catalítica SHP-2.
- Comprender el papel de sus dominios SH2 en la inhibición y activación de enzimas.
Principales métodos:
- Se utilizó cristalografía de rayos X para determinar la estructura de SHP-2.
- Se realizó un análisis estructural de alta resolución (2.0 angstroms).
Principales resultados:
- El dominio N-terminal SH2 inhibe directamente el dominio de la fosfatasa bloqueando el sitio activo en ausencia de ligandos.
- La unión del ligando al dominio N-terminal SH2 induce un cambio conformacional, activando la enzima.
- El dominio C-terminal SH2 contribuye a la especificidad del ligando y la energía de unión, pero no a la activación directa.
Conclusiones:
- SHP-2 funciona como un interruptor conformacional, regulado por su dominio N-terminal SH2.
- La estructura de SHP-2 revela un nuevo mecanismo para la regulación de la fosfatasa que implica la inhibición intramolecular y la activación a través de la unión a las fosfoproteínas.
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