TY - JOUR
T1 - Structural basis for the binding of SNAREs to the multisubunit tethering complex Dsl1
AU - Travis, Sophie M.
AU - DAmico, Kevin
AU - Yu, I. Mei
AU - McMahon, Conor
AU - Hamid, Safraz
AU - Ramirez-Arellano, Gabriel
AU - Jeffrey, Philip D.
AU - Hughson, Frederick M.
N1 - Publisher Copyright:
© 2020 Travis et al.
PY - 2020/7/24
Y1 - 2020/7/24
N2 - Multisubunit-tethering complexes (MTCs) are large (250 to >750 kDa), conserved macromolecular machines that are essential for soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion in all eukaryotes.MTCs are thought to organizemembrane trafficking by mediating the initial long-range interaction between a vesicle and its target membrane and promoting the formation of membrane-bridging SNARE complexes. Previously, we reported the structure of the yeast Dsl1 complex, the simplest known MTC, which is essential for coat protein I (COPI) mediated transport fromthe Golgi to the endoplasmic reticulum(ER). This structure suggests how theDsl1 complex might tether a vesicle to its target membrane by binding at one end to the COPI coat and at the other to ER-associated SNAREs. Here, we used X-ray crystallography to investigate these Dsl1-SNARE interactions in greater detail. The Dsl1 complex comprises three subunits that together form a two-legged structure with a central hinge. We found that distal regions of each leg bind N-terminal Habc domains of the ER SNAREs Sec20 (a Qb-SNARE) and Use1 (a Qc-SNARE). The observed binding modes appear to anchor the Dsl1 complex to the ER target membrane while simultaneously ensuring that both SNAREs are in open conformations, with their SNARE motifs available for assembly. The proximity of the two SNARE motifs, and therefore their ability to enter the same SNARE complex, will depend on the relative orientation of the two Dsl1 legs. These results underscore the critical roles of SNARE N-terminal domains in mediating interactions with other elements of the vesicle docking and fusion machinery.
AB - Multisubunit-tethering complexes (MTCs) are large (250 to >750 kDa), conserved macromolecular machines that are essential for soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion in all eukaryotes.MTCs are thought to organizemembrane trafficking by mediating the initial long-range interaction between a vesicle and its target membrane and promoting the formation of membrane-bridging SNARE complexes. Previously, we reported the structure of the yeast Dsl1 complex, the simplest known MTC, which is essential for coat protein I (COPI) mediated transport fromthe Golgi to the endoplasmic reticulum(ER). This structure suggests how theDsl1 complex might tether a vesicle to its target membrane by binding at one end to the COPI coat and at the other to ER-associated SNAREs. Here, we used X-ray crystallography to investigate these Dsl1-SNARE interactions in greater detail. The Dsl1 complex comprises three subunits that together form a two-legged structure with a central hinge. We found that distal regions of each leg bind N-terminal Habc domains of the ER SNAREs Sec20 (a Qb-SNARE) and Use1 (a Qc-SNARE). The observed binding modes appear to anchor the Dsl1 complex to the ER target membrane while simultaneously ensuring that both SNAREs are in open conformations, with their SNARE motifs available for assembly. The proximity of the two SNARE motifs, and therefore their ability to enter the same SNARE complex, will depend on the relative orientation of the two Dsl1 legs. These results underscore the critical roles of SNARE N-terminal domains in mediating interactions with other elements of the vesicle docking and fusion machinery.
UR - http://www.scopus.com/inward/record.url?scp=85088680217&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85088680217&partnerID=8YFLogxK
U2 - 10.1074/jbc.RA120.013654
DO - 10.1074/jbc.RA120.013654
M3 - Article
C2 - 32409579
AN - SCOPUS:85088680217
SN - 0021-9258
VL - 295
SP - 10125
EP - 10135
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 30
ER -