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Un cofactor de manganeso (IV) / hierro (III) en la Chlamydia trachomatis ribonucleótido reductasa
Wei Jiang1, Danny Yun, Lana Saleh
1Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
Science (New York, N.Y.)
|May 26, 2007
Resumen
La ribonucleótido reductasa (RNR) de Chlamydia trachomatis utiliza un nuevo cofactor de manganeso (IV) / hierro (III) para la iniciación de radicales, que difiere del mecanismo típico de radicales tirosilo que se encuentra en otros RNR.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Enzimología Enzimología.
- Microbiología Microbiología.
Sus antecedentes:
- Las ribonucleotidas reductasas de clase I (RNR) son enzimas esenciales para la síntesis y reparación del ADN.
- Los RNR convencionales utilizan un cofactor diironio y un radical tirosilo para la reducción del sustrato.
- Anteriormente se pensaba que el RNR de Chlamydia trachomatis seguía este mecanismo convencional a pesar de carecer del radical tirosilo.
Objetivo del estudio:
- Para investigar el mecanismo de iniciación radical de Chlamydia trachomatis ribonucleótido reductasa (RNR).
- Identificar el cofactor responsable de la generación de radicales en este RNR atípico.
Principales métodos:
- Los ensayos de actividad enzimática analizan la actividad enzimática.
- Las técnicas espectroscópicas (por ejemplo, EPR, espectroscopia de Mössbauer)
- Caracterización bioquímica de las características.
Principales resultados:
- El RNR de Chlamydia trachomatis carece del radical tirosilo canónico.
- Se identificó un cofactor estable de manganeso (IV) / hierro (III) en la subunidad R2.
- Este cofactor Mn{IV}/Fe{III} inicia directamente la formación de radicales en la subunidad R1.
Conclusiones:
- La RNR de Chlamydia trachomatis emplea un mecanismo único de iniciación de radicales.
- El cofactor manganeso (IV) / hierro (III) representa una nueva estrategia para la función RNR.
- Este hallazgo amplía nuestra comprensión de la diversidad y evolución de RNR.
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