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Synthesis of an Intein-mediated Artificial Protein Hydrogel
Published on: January 27, 2014
La estructura cristalina de la invasina: una proteína bacteriana que se une a la integrina
Z A Hamburger1, M S Brown, R R Isberg
1Division of Biology 156-29, Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA.
Science (New York, N.Y.)
|October 9, 1999
Resumen
La proteína Yersinia pseudotuberculosis invasin se une a las integrinas de las células huésped más fuertemente que la fibronectina. Su estructura revela una evolución convergente, con la invasina presentando una superficie optimizada para la unión a la integrina.
Área de la Ciencia:
- Microbiología y Biología Estructural.
- Mecanismos moleculares de la patogénesis bacteriana.
Sus antecedentes:
- La proteína Yersinia pseudotuberculosis invasin facilita la invasión bacteriana al unirse a las integrinas de las células huésped.
- Las integrinas de las células huésped son cruciales para la adhesión celular y la señalización, y son blancos naturales para los patógenos.
Objetivo del estudio:
- Para dilucidar la base estructural de la interacción de alta afinidad de la invasina con las integrinas de la célula huésped.
- Para comparar las características estructurales de la invasina con los ligandos naturales de la integrina como la fibronectina.
Principales métodos:
- Se utilizó la cristalografía de rayos X para determinar la estructura cristalina de 2,3 angstroms de la región extracelular invasina.
- Se realizaron comparaciones estructurales entre los dominios invasina y fibronectina tipo III.
Principales resultados:
- La estructura de la invasina reveló cinco dominios que forman una varilla de 180 angstrom, que se asemeja a los dominios en tándem de la fibronectina tipo III.
- Se identificaron residuos clave involucrados en la unión a la integrina tanto en la invasina como en la fibronectina.
- A pesar de la similitud funcional, la invasina y la fibronectina exhiben pliegues estructurales y topografías de superficie distintos.
Conclusiones:
- La estructura de Invasin demuestra una evolución convergente, imitando los sustratos del huésped para optimizar la unión de la integrina.
- Invasin presenta una superficie altamente adaptada para el compromiso potente de la integrina, superando a los ligandos naturales en afinidad.
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