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Estructura y mecanismo del transportador de glicerol-3-fosfato de Escherichia coli
Yafei Huang1, M Joanne Lemieux, Jinmei Song
1Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
Science (New York, N.Y.)
|August 2, 2003
Resumen
La estructura de GlpT, un transportador de glicerol-3-fosfato, revela una pseudo simetría doble y un poro central con argininas que forman el sitio de unión al sustrato. Es probable que este transportador funcione a través de un mecanismo de acceso alternativo.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Transporte de la membrana Transporte de la membrana
Sus antecedentes:
- La superfamilia principal de facilitadores es el grupo más grande de transportadores de membrana secundaria.
- La comprensión de los mecanismos de transporte es crucial para la función celular.
Objetivo del estudio:
- Para determinar la estructura de alta resolución de GlpT, un transportador de glicerol-3-fosfato. para determinar la estructura de alta resolución de GlpT, un transportador de glicerol-3-fosfato. para determinar la estructura de alta resolución de GlpT, un transportador de glicerol-3-fosfato. para determinar la estructura de alta resolución de GlpT, un transportador de glicerol-3-fosfato.
- Para dilucidar el mecanismo de la translocación del sustrato a través de la membrana.
Principales métodos:
- Se utilizó cristalografía de rayos X para obtener la estructura de resolución de 3,3 angstroms de GlpT.
- El análisis estructural se centró en la identificación de sitios de unión al sustrato y cambios conformacionales.
Principales resultados:
- La estructura de GlpT exhibe una simetría pseudo-doble entre sus mitades amino- y carboxilo-terminales.
- Un poro central, cerrado al periplasma, contiene dos argininas identificadas como el sitio de unión al sustrato.
- La unión al sustrato induce una conformación proteica más compacta.
Conclusiones:
- Es probable que GlpT opere a través de un único sitio de enlace y un mecanismo de acceso alternativo.
- Se propone un tipo de movimiento de interruptor de balanceo para la función de transporte de GlpT.
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