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. 2015 May;25(5):551-60.
doi: 10.1038/cr.2015.47. Epub 2015 Apr 24.

Cryo-EM structure of SNAP-SNARE assembly in 20S particle

Qiang Zhou  1 , Xuan Huang  1 , Shan Sun  1 , Xueming Li  2 , Hong-Wei Wang  2 , Sen-Fang Sui  1
Affiliations

Cryo-EM structure of SNAP-SNARE assembly in 20S particle

Qiang Zhou et al. Cell Res. 2015 May.

Abstract

N-ethylmaleimide-sensitive factor (NSF) and α soluble NSF attachment proteins (α-SNAPs) work together within a 20S particle to disassemble and recycle the SNAP receptor (SNARE) complex after intracellular membrane fusion. To understand the disassembly mechanism of the SNARE complex by NSF and α-SNAP, we performed single-particle cryo-electron microscopy analysis of 20S particles and determined the structure of the α-SNAP-SNARE assembly portion at a resolution of 7.35 Å. The structure illustrates that four α-SNAPs wrap around the single left-handed SNARE helical bundle as a right-handed cylindrical assembly within a 20S particle. A conserved hydrophobic patch connecting helices 9 and 10 of each α-SNAP forms a chock protruding into the groove of the SNARE four-helix bundle. Biochemical studies proved that this structural element was critical for SNARE complex disassembly. Our study suggests how four α-SNAPs may coordinate with the NSF to tear the SNARE complex into individual proteins.

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Figures

Figure 1
Figure 1
Cryo-EM 3D reconstruction and atomic model docking of the upper part of ND-20S. (A) A representative micrograph of vitrified ND-20S particles with typical particles marked by red circles. (B) Typical 2D class averages of ND-20S. The relative tilt between the upper part and lower parts of the complex is labeled in the first class average. (C) Typical 2D class averages of the upper portion of ND-20S. (D) Typical 2D class averages of 20S particle in the top view. (E) Top and (F) side views of the ND-20S upper part 3D map docked with atomic models of α-SNAP and SNARE complex shown in different colors for clarity. (G) Docking of atomic model of the SNARE complex in the central portion of the 3D reconstruction.
Figure 2
Figure 2
The interaction between α-SNAP protomers. (A) Top and (B) side views of atomic models of α-SNAP tetramer. (C) Enlarged view of the protomer interface with relevant charged residues labeled with ball and stick model. The helices are numbered according to the crystal structure in the two protomers.
Figure 3
Figure 3
The helix hairpin tip of α-SNAP interacting with the SNARE complex. (A) Cryo-EM 3D map of the upper part of ND-20S docked with four α-SNAPs. (B) Top view of the marked slab in A. (C) Side view of the cryo-EM map docked with only one α-SNAP protomer, with the other three α-SNAP protomers removed for clarity. The conserved hydrophobic residues around the “chock” are shown in purple. (D) Enlarged view of the “chock” structural element in C. (E) Effects of α-SNAP mutations on the SNARE complex disassembly (upper panel) or on the α-SNAP-dependent binding of NSF to the SNARE complex (lower panel). (F) Histogram of the band intensity relative to the wild type as shown in E.
Figure 4
Figure 4
Model of SNARE complex disassembly by the coordinated action of NSF and α-SNAP in a 20S particle. The SNARE complex inserted into the membrane binds to α-SNAPs and NSF to form the 20S particle in the presence of ATP (A). During the ATP hydrolysis, the NSF D1 ring rotates counter-clockwise from the top view, which might induce a rotation of the tetrameric α-SNAP assembly in the same direction, and the up-to-down motion of the NSF N-domain might cause α-SNAP to move accordingly (B). These two types of movement may lead to the sliding of the “chock” structure along the groove of the SNARE complex (C), thus disassembling the SNARE complex after phosphate release (D).
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References

    1. Söllner T, Whiteheart SW, Brunner M, et al. SNAP receptors implicated in vesicle targeting and fusion. Nature. 1993;362:318–324. - PubMed
    1. Rothman JE. Mechanisms of intracellular protein transport. Nature. 1994;372:55–63. - PubMed
    1. Sutton RB, Fasshauer D, Jahn R, Brunger AT. Crystal structure of a SNARE complex involved in synaptic exocytosis at 2.4 Å resolution. Nature. 1998;395:347–353. - PubMed
    1. Antonin W, Fasshauer D, Becker S, Jahn R, Schneider TR. Crystal structure of the endosomal SNARE complex reveals common structural principles of all SNAREs. Nat Struct Biol. 2002;9:107–111. - PubMed
    1. Jahn R, Scheller RH. SNAREs--engines for membrane fusion. Nat Rev Mol Cell Biol. 2006;7:631–643. - PubMed

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