Structure of the Sec13-Sec16 edge element, a template for assembly of the COPII vesicle coat
Ancestral coatomer element 1 (ACE1) proteins assemble latticework coats for COPII vesicles and the nuclear pore complex. The ACE1 protein Sec31 and Sec13 make a 2:2 tetramer that forms the edge element of the COPII outer coat. In this study, we report that the COPII accessory protein Sec16 also cont...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Rockefeller University Press
2014
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| Online Access: | http://hdl.handle.net/1721.1/85628 https://orcid.org/0000-0001-8012-1512 |
| Summary: | Ancestral coatomer element 1 (ACE1) proteins assemble latticework coats for COPII vesicles and the nuclear pore complex. The ACE1 protein Sec31 and Sec13 make a 2:2 tetramer that forms the edge element of the COPII outer coat. In this study, we report that the COPII accessory protein Sec16 also contains an ACE1. The 165-kD crystal structure of the central domain of Sec16 in complex with Sec13 was solved at 2.7-Å resolution. Sec16 and Sec13 also make a 2:2 tetramer, another edge element for the COPII system. Domain swapping at the ACE1–ACE1 interface is observed both in the prior structure of Sec13–Sec31 and in Sec13–Sec16. A Sec31 mutant in which domain swapping is prevented adopts an unprecedented laminated structure, solved at 2.8-Å resolution. Our in vivo data suggest that the ACE1 element of Sec31 can functionally replace the ACE1 element of Sec16. Our data support Sec16 as a scaffold for the COPII system and a template for the Sec13–Sec31 coat. |
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