STRUCTURE OF THE SEC13-SEC16 EDGE ELEMENT

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。次级项目的主要支助 子项目的主要研究者可能是由其他来源提供的， 包括其它NIH来源。 为子项目列出的总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 祖先coatomer元件1（ACE 1）蛋白组装COPII囊泡和核孔复合物的晶格外套。ACE 1蛋白Sec 31和Sec 13形成2：2四聚体，形成COPII外涂层的边缘元件。在这项研究中，我们报告说，COPII辅助蛋白Sec 16也含有ACE 1。Sec 16与Sec 13复合的中心结构域的165-kD晶体结构以2.7-<$D分辨率解析。Sec 16和Sec 13还形成2：2四聚体，这是COPII系统的另一个边缘元件。ACE 1接口在Sec 13的现有结构中均得到观察Sec 31和Sec 13Sec16.一个Sec 31突变体，其中结构域交换被阻止，采用了前所未有的层压结构，解决了2.8-²分辨率。我们的体内数据表明，ACE 1元件Sec 31可以在功能上取代ACE 1元件Sec 16。我们的数据支持Sec 16作为COPII系统的支架和Sec 13的模板Sec 31外套

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Ancestral coatomer element 1 (ACE1) proteins assemble latticework coats for COPII vesicles and the nuclear pore complex. The ACE1 pro- tein 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-¿ resolution. Sec16 and Sec13 also make a 2:2 tetramer, another edge element for the COPII system.Domain swapping at the ACE1ACE1 interface is ob- served both in the prior structure of Sec13Sec31 and in Sec13Sec16. A Sec31 mutant in which domain swap- ping is prevented adopts an unprecedented laminated structure, solved at 2.8-¿ 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 Sec13Sec31 coat.