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Los dominios similares a las helicasas de las enzimas de restricción de tipo III desencadenan la difusión de largo

Friedrich W Schwarz¹, Júlia Tóth, Kara van Aelst

¹DNA motors group, Biotechnology Center, Technische Universität Dresden, 01062 Dresden, Germany.

Science (New York, N.Y.)

|April 20, 2013

Resumen

Las adenosina trifosfatasas (ATPasas) pueden desencadenar la difusión de ADN de largo alcance. La enzima EcoP15I utiliza su actividad ATPasa para cambiar estados, permitiendo el movimiento independiente de ATP a lo largo del ADN para la verificación y señalización de objetivos.

Área de la Ciencia:

Biología Molecular Biología Molecular
La bioquímica es la bioquímica.
La genómica es la genómica.

Sus antecedentes:

Las helicasas son trifosfatasas de adenosina esenciales (ATPases) cruciales para varios procesos de metabolismo del genoma.
Comprender las diversas funciones de las ATPasas, particularmente aquellas con dominios similares a las helicasas, es vital para comprender la dinámica del ADN.

Objetivo del estudio:

Investigar una nueva funcionalidad de las ATPasas con dominios similares a las helicasas.
Para dilucidar el mecanismo por el cual la hidrólisis de ATP influye en el comportamiento de las proteínas en el ADN.
Explorar el papel de este mecanismo en la verificación y señalización del sitio objetivo del ADN.

Principales métodos:

Se empleó microscopía de fluorescencia de molécula única para observar la dinámica de las proteínas en el ADN.
El estudio se centró en la enzima de restricción de tipo III EcoP15I y su actividad ATPasa.
Se realizó un análisis cuantitativo de la hidrólisis de ATP y la difusión de proteínas.

Principales resultados:

La hidrólisis de ATP por EcoP15I desencadena un cambio a un estado estructural distinto.
Este estado permite la difusión unidimensional (1D) de largo alcance y independiente del ATP de la enzima en el ADN.
El mecanismo de conmutación requiere la unión al sitio objetivo y la hidrólisis de aproximadamente 30 moléculas de ATP.

Conclusiones:

Las ATPasas con dominios similares a las helicasas poseen una función no reconocida anteriormente: permitir la difusión de proteínas independientes del ATP en el ADN.
Este mecanismo impulsado por la ATPasa está involucrado en la verificación del sitio objetivo del ADN y la señalización 1D.
Los hallazgos ofrecen información sobre las funciones conservadas de las ATPasas en el metabolismo del ADN, como en las vías de reparación.

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