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El clúster [4Fe4S] de la ADN polimerasa ε de la levadura es redox activo y puede someterse a la señalización mediada

Miguel N Pinto¹, Josy Ter Beek², Levi A Ekanger^1,3

¹Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.

Journal of the American Chemical Society

|September 24, 2021

Resumen

La ADN polimerasa ε (Pol ε) utiliza un grupo [4Fe4S] para la replicación. La oxidación inactiva la enzima, pero la reducción, potencialmente a través del transporte de carga de ADN, restaura la actividad.

Área de la Ciencia:

La bioquímica
Biología molecular
Química bioorgánica

Sus antecedentes:

Muchas enzimas de replicación y reparación de ADN utilizan grupos [4Fe4S].
El dominio catalítico de la ADN polimerasa ε (Pol ε), Pol2_CORE, contiene un grupo [4Fe4S].

Objetivo del estudio:

Para investigar las propiedades redox del grupo [4Fe4S] en Pol2_CORE.
Determinar el impacto de la oxidación y reducción de los racimos sobre la actividad de Pol ε.

Principales métodos:

Utilizó la electroquímica del ADN para estudiar las características redox.
Empleó una variante de Pol2_CORE con deficiencia de exonucleasa (Pol2_COREexo^-) y un mutante sin clúster [4Fe4S].
Se examinó el efecto de la rereducción utilizando la enzima de reparación del ADN EndoIII.

Principales resultados:

El Pol2 oxidado exhibió una señal redox catódica, ausente en el mutante libre de clúster [4Fe4S].
La oxidación de proteínas disminuyó significativamente la actividad de polimerización.
La reducción restauró la actividad de la polimerasa, y EndoIII facilitó esta restauración a través del transporte de carga de ADN.

Conclusiones:

El grupo [4Fe4S] en Pol ε es redox-activo e influye en la función de la polimerasa.
El transporte de carga de ADN puede mediar la transferencia de electrones de las enzimas de reparación a Pol ε, modulando su actividad.

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