Molecular architecture of the multisubunit homotypic fusion and vacuole protein sorting (HOPS) tethering complex.
Membrane fusion within the eukaryotic endomembrane system depends on the initial recognition of Rab GTPase on transport vesicles by multisubunit tethering complexes and subsequent coupling to SNARE-mediated fusion. The conserved vacuolar/lysosomal homotypic fusion and vacuole protein sorting (HOPS) tethering complex combines both activities. Here we present the overall structure of the fusion-active HOPS complex. Our data reveal a flexible ≈30-nm elongated seahorse-like structure, which can adopt contracted and elongated shapes. Surprisingly, both ends of the HOPS complex contain a Rab-binding subunit: Vps41 and Vps39. The large head contains in addition to Vps41 the SNARE-interacting Vps33, whereas Vps39 is found in the bulky tip of its tail. Vps11 and Vps18 connect head and tail. Our data suggest that HOPS bridges Ypt7-positive membranes and chaperones SNAREs at fusion sites.
Biochemistry Section, Department of Biology,  University of Osnabrück, 49076 Osnabrück,  Germany.
Cornelia
C
Bröcker
Anne
A
Kuhlee
Christos
C
Gatsogiannis
Henning J kleine
HJ
Balderhaar
Carina
C
Hönscher
Siegfried
S
Engelbrecht-Vandré
Christian
C
Ungermann
Stefan
S
Raunser
D001665:Binding Sites; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008561:Membrane Fusion; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism*; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D055672:Static Electricity; D014617:Vacuoles / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000378:metabolism
D046912:Multiprotein Complexes; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D020691:rab GTP-Binding Proteins