Figure 5: Structural changes of Sso2 induced by Sec3N.
From: Sec3 promotes the initial binary t-SNARE complex assembly and membrane fusion
(a) Structural comparison of free Sso1 and Sso2 in complex with Sec3. Three orthogonal views are displayed to show the structural changes at the SNARE motif and Hc region. Boxed parts are enlarged under the images for a clear view of the structural changes. In comparison to Sso1, the N terminus of SNARE motif (‘H3’) in Sso2 bends towards Ha by 22°. (b) Conformational transition of Helix 2 (‘HL2’) in the linker region. ‘HL2’ of Sso2 is mostly disordered when bound to Sec3N. (c) A close-up view of the conformational changes in the linker region. Residues forming the hydrophobic core are shown as sticks. (d) Superposition of Sec3-bound Sso2 (blue), free Sso1 (pink) and the Sso1-Sec9–Snc1 complex (green, cyan and orange; PDB code: 3B5N). The alignment was centered on the SNARE motif of Sso. Note that HL2 (dotted oval in orange) appears in a position that hinders Sec9 binding to Sso.
