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Estructura de la citocromo c nitrito reductasa
O Einsle1, A Messerschmidt, P Stach
1Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Martinsried, Germany. einsle@biochem.mpg.de
Nature
|August 10, 1999
Resumen
Se determinó la estructura cristalina de la citocromo c nitrito reductasa, revelando su papel en el ciclo biológico del nitrógeno. Esta enzima facilita la reducción del nitrito a amoníaco, crucial para el metabolismo energético anaeróbico.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Microbiología Microbiología.
- Biología Estructural Biología estructural.
Sus antecedentes:
- La citocromo c nitrito reductasa es vital para el ciclo biológico del nitrógeno, catalizando la conversión del nitrito en amoníaco.
- Desempeña un papel clave en el metabolismo energético anaeróbico de la amonificación disimilatoria de nitrato.
Objetivo del estudio:
- Para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum deleyianum. para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum deleyianum. para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum deleyianum. para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum. para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum deleyianum. para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum. para determinar la estructura cristalina de la citocromo c nitrito reductasa de Sulfurospirillum.
- Para dilucidar el mecanismo de reacción de la enzima y el sitio activo.
- Para identificar familias de proteínas conservadas con arreglos hemo similares.
Principales métodos:
- Cristalografía de rayos X con rayos X.
- Métodos de dispersión anómala de múltiples longitudes de onda (MAD)
- El análisis espectroscópico.
Principales resultados:
- Se resolvió la estructura cristalina de la citocromo c nitrito reductasa, revelando un dimero funcional.
- La enzima contiene 10 grupos hemo de tipo c y un inusual hemo de alto espín coordinado con lisina en el sitio activo.
- Se propuso un esquema de reacción para la transformación de nitrito basado en datos estructurales y espectroscópicos.
Conclusiones:
- La estructura determinada proporciona información sobre el mecanismo catalítico de la reducción del nitrito.
- Se identificó una familia conservada de citocromos multihemos con orientación hemo conservada pero estructura y función variables.
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