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Structure of HIV-1 Capsid Assemblies by Cryo-electron Microscopy and Iterative Helical Real-space Reconstruction

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Published on: August 9, 2011

Virología estructural. La plasticidad conformal de una cápside retroviral nativa revelada por la cristalografía de

G Obal¹, F Trajtenberg², F Carrión³

¹Institut Pasteur de Montevideo, Unit of Protein Biophysics, Mataojo 2020, 11400, Montevideo, Uruguay. Departamento de Inmunobiología, Facultad de Medicina, Universidad de la República, Avenida General Flores 2125, 11800, Montevideo, Uruguay.

Science (New York, N.Y.)

|June 6, 2015

Resumen

Los investigadores determinaron la estructura de la proteína de la cápside del virus de la leucemia bovina, revelando cómo sus hexámeres se ensamblan en estructuras similares al núcleo. Este hallazgo explica la formación del núcleo retroviral y proporciona información sobre los mecanismos de ensamblaje viral.

Área de la Ciencia:

Biología Estructural Biología Estructural
Virología Virología.
La bioquímica es la bioquímica.

Sus antecedentes:

Los retrovirus requieren autoensamblaje de proteínas cápsidas en partículas centrales para la infectividad.
El alto polimorfismo de los núcleos retrovirales ha limitado los estudios estructurales detallados.

Objetivo del estudio:

Para determinar la estructura de rayos X de alta resolución de la proteína nativa del cápsido del virus de la leucemia bovina (CA).
Para dilucidar los principios de ensamblaje de núcleos retrovirales a nivel molecular.

Principales métodos:

Se utilizó cristalografía de rayos X para determinar la estructura tridimensional de la proteína CA del virus de la leucemia bovina.
Análisis de la disposición de las subunidades dentro de los hexámeres y su montaje en matrices pseudohexagonales.

Principales resultados:

La proteína CA del virus de la leucemia bovina forma hexámeres con desviaciones de la perfecta simetría hexagonal.
Estos hexámeres se ensamblan en matrices pseudohexagonales 2D que imitan núcleos retrovirales maduros.
Los contactos casi equivalentes, incluidas las flexibles interacciones laterales triméricas, estabilizan la red mientras se conservan las interfaces diméricas.

Conclusiones:

La conformación de la proteína cápside está influenciada por interacciones de largo alcance, lo que permite el ensamblaje de hexámero en partículas de núcleo cerrado.
La comprensión de estas dinámicas estructurales proporciona información sobre los mecanismos fundamentales de la formación y maduración del núcleo retroviral.

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