Department of Clinical Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom.
Proc Natl Acad Sci U S A. 2013 Aug 13;110(33):13345-50. doi: 10.1073/pnas.1307074110. Epub 2013 Jul 30.
The multisubunit homotypic fusion and vacuole protein sorting (HOPS) membrane-tethering complex is required for late endosome-lysosome and autophagosome-lysosome fusion in mammals. We have determined the crystal structure of the human HOPS subunit Vps33A, confirming its identity as a Sec1/Munc18 family member. We show that HOPS subunit Vps16 recruits Vps33A to the human HOPS complex and that residues 642-736 are necessary and sufficient for this interaction, and we present the crystal structure of Vps33A in complex with Vps16(642-736). Mutations at the binding interface disrupt the Vps33A-Vps16 interaction both in vitro and in cells, preventing recruitment of Vps33A to the HOPS complex. The Vps33A-Vps16 complex provides a structural framework for studying the association between Sec1/Munc18 proteins and tethering complexes.
多亚基同源融合和液泡蛋白分选（HOPS）膜连接复合物对于哺乳动物晚期内体-溶酶体和自噬体-溶酶体融合是必需的。我们已经确定了人源 HOPS 亚基 Vps33A 的晶体结构，证实其为 Sec1/Munc18 家族成员。我们表明，HOPS 亚基 Vps16 将 Vps33A 募集到人源 HOPS 复合物中，并且残基 642-736 是该相互作用所必需且充分的，并且我们呈现了 Vps33A 与 Vps16（642-736）复合物的晶体结构。结合界面上的突变在体外和细胞内均破坏了 Vps33A-Vps16 相互作用，从而阻止了 Vps33A 向 HOPS 复合物的募集。Vps33A-Vps16 复合物为研究 Sec1/Munc18 蛋白与连接复合物之间的关联提供了结构框架。
