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Vista estructural de la interacción Ran-Importin beta a una resolución de 2.3 A

I R Vetter¹, A Arndt, U Kutay

¹Max-Planck-Institut für molekulare Physiologie, Dortmund, Germany.

|June 15, 1999

Resumen

Los investigadores determinaron la estructura de la importina beta, un receptor de transporte nuclear clave, unido al Ran-GTP. Esto revela cómo Importin beta interactúa con Ran para regular el transporte nuclear de las macromoléculas.

Área de la Ciencia:

Biología Molecular Biología Molecular
Biología Estructural Biología estructural.
Biología celular Biología celular.

Sus antecedentes:

Las proteínas de la familia de las importinas beta son receptores cruciales de transporte nuclear.
Median el transporte de macromoléculas a través de complejos de poros nucleares.
Su función está regulada por la interacción con la proteína de unión al GTP Ran.

Objetivo del estudio:

Para aclarar la base estructural de la interacción de Importin beta-Ran.
Para entender el mecanismo de regulación del transporte nuclear por Ran.

Principales métodos:

Determinación estructural tridimensional mediante cristalografía de rayos X. Determinación estructural tridimensional mediante cristalografía de rayos X.
Formación de complejo entre el fragmento beta de Importin y Ran unido a GppNHp (un análogo de GTP).

Principales resultados:

Se determinó la estructura de un complejo entre Importin beta y el análogo Ran-GTP.
Importin beta se compone de 10 tandem HEAT/Armadillo como repeticiones que forman una forma de media luna.
El sitio cóncavo de Importin beta interactúa con el Ran-trifosfato.
El sitio de unión Ran para Importin beta es distinto del dominio de unión Ran de RanBP2.

Conclusiones:

La estructura determinada proporciona información sobre el mecanismo del transporte nuclear.
Destaca el papel de las características estructurales de Importin beta en la unión Ran.
Este trabajo aclara las distintas interfaces de enlace de Ran.

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