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La estructura atómica del núcleo cúbico del complejo multienzimático de piruvato deshidrogenasa
A Mattevi1, G Obmolova, E Schulze
1Department of Chemistry, University of Groningen, The Netherlands.
Science (New York, N.Y.)
|March 20, 1992
Resumen
La estructura cristalina de los complejos multienzimales de piruvato deshidrogenasa revela un núcleo cúbico de 24 subunidades. Esta estructura atómica proporciona un marco para la comprensión de estos grandes complejos enzimáticos.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Estructural Biología estructural.
- Enzimología Enzimología.
Sus antecedentes:
- Los complejos multienzimales de piruvato deshidrogenasa son estructuras grandes y altamente simétricas.
- Estos complejos están compuestos por piruvato deshidrogenasa, dihidrolipoil transacetilasa y lipoamida deshidrogenasa.
Objetivo del estudio:
- Para determinar la estructura cristalina tridimensional del dominio catalítico de Azotobacter vinelandii dihydrolipoyl transacetylase. para determinar la estructura cristalina tridimensional del dominio catalítico de Azotobacter vinelandii dihydrolipoyl transacetylase. para determinar la estructura cristalina tridimensional del dominio catalítico de Azotobacter vinelandii dihydrolipoyl transacetylase. para determinar la estructura cristalina tridimensional del dominio catalítico de Azotobacter vinelandii dihydrolipoyl transacetylase. para determinar la estructura cristalina tridimensional del dominio catalítico de Azotobacter vinelandii dihydrolipoyl transacetylase. para determinar la estructura cristalina tridimensional del dominio catalítico de Azotobacter vinelandii.
- Para dilucidar la organización estructural del núcleo del complejo multienzimático piruvato deshidrogenasa.
Principales métodos:
- Cristalografía de rayos X con una resolución de 2,6 angstroms.
- Análisis del ensamblaje de la subunidad y la accesibilidad al canal del sitio activo.
Principales resultados:
- Ocho trímeres de dihidrolipoil transacetilasa se ensamblan en un cubo truncado hueco (borda de 125 A).
- El canal del sitio activo (29 A de largo) requiere la entrada de la coenzima A desde el interior y la lipoamida desde el exterior.
- La topología del trímero es idéntica a la de la cloramfenicol acetiltransferasa.
Conclusiones:
- La estructura atómica del núcleo cúbico de 24 subunidades ofrece un modelo para la piruvato deshidrogenasa y los complejos multienzimales relacionados.
- Comprender el marco estructural es crucial para descifrar la función y regulación del complejo enzimático.
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