A Pseudo-Atomic Model of the COPII Cage Obtained from CryoEM and Mass Spectrometry Analyses

COPII vesicles transport proteins from the ER to the Golgi apparatus. Previous cryoEM structures of the COPII cage lacked the resolution necessary to determine the residues of Sec13 and Sec31 that mediate assembly and flexibility of the COPII cage. Here we present a 12Å-resolution structure of the C...

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Detalles Bibliográficos
Autores principales: Noble, Alex J., Zhang, Qian, O’Donnell, Jason, Hariri, Hanaa, Bhattacharya, Nilakshee, Marshall, Alan G., Stagg, Scott M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2012
Materias:
Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3565055/
https://www.ncbi.nlm.nih.gov/pubmed/23262493
http://dx.doi.org/10.1038/nsmb.2467
Descripción
Sumario:COPII vesicles transport proteins from the ER to the Golgi apparatus. Previous cryoEM structures of the COPII cage lacked the resolution necessary to determine the residues of Sec13 and Sec31 that mediate assembly and flexibility of the COPII cage. Here we present a 12Å-resolution structure of the COPII cage, where the tertiary structure of Sec13 and Sec31 is clearly identifiable. We employ this structure and a homology model of the Sec13-Sec31 complex to create a reliable pseudo-atomic model of the COPII cage. We combined this model with hydrogen/deuterium exchange mass spectrometry analysis to characterize four distinct contact regions at the vertices of the COPII cage. Furthermore, we found that the 2-fold symmetry of the Sec31 dimeric region of Sec13-31 is broken on cage formation, and that the resulting hinge is essential to form the proper edge geometry in COPII cages.

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