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Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
Published on: April 15, 2013
El sitio radical en la ribonucleótido reductasa clamidial define una nueva subclase R2
Martin Högbom1, Pål Stenmark, Nina Voevodskaya
1Department of Biochemistry and Biophysics, Stockholm University, Roslagstullsbacken 15, Albanova University Center, SE-10691 Stockholm, Sweden.
Science (New York, N.Y.)
|July 13, 2004
Resumen
La proteína R2 de la reductasa de ribonucleótido de Chlamydia trachomatis carece de un sitio de radical tirosilo. En cambio, forma un radical acoplado al hierro, lo que sugiere una nueva clase de proteínas R2 involucradas en la síntesis del ADN.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
Sus antecedentes:
- La ribonucleótido reductasa (RNR) es crucial para la síntesis del ADN, que requiere desoxirribonucleótidos.
- Los RNR de clase I, específicamente la proteína R2, suelen presentar un sitio de diirón que genera un radical libre tirosilo esencial para la actividad.
Objetivo del estudio:
- Para investigar las propiedades estructurales y funcionales de la proteína R2 de Chlamydia trachomatis.
- Para caracterizar las especies radicales y la coordinación del sitio metálico en C. trachomatis R2.
Principales métodos:
- Los estudios estructurales incluyen estudios estructurales.
- La espectroscopia de resonancia paramagnética de electrones (EPR, por sus siglas en inglés) es una espectroscopia de resonancia paramagnética de electrones.
- La reconstitución de las proteínas.
Principales resultados:
- La proteína R2 de C. trachomatis carece del sitio del radical tirosílico canónico que se encuentra en otros RNR de clase I.
- Tras la reconstitución, la proteína forma un radical acoplado al hierro.
- El sitio metálico de diirón exhibe una estructura de coordinación análoga a las de las diironoxidasas/monoxigenasas.
Conclusiones:
- La proteína R2 de C. trachomatis representa una subclase distinta de las proteínas R2.
- El radical acoplado al hierro probablemente juega un papel en el mecanismo RNR.
- Este grupo recién identificado de proteínas R2 está presente en ocho organismos, incluidos tres patógenos humanos.
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