Figure 3.

SNAP-25 promotes the assembly of the SNARE complex on tagmin. GST–tagmin was incubated alone (lane 1) or with His₆–SNAP-25 (lanes 3, 6–8, 10, and 13–15) and/or full-length syntaxin 1B (lanes 2, 5, 6, 8, 9, 12, 13, and 15) and/or VAMP–His₆ (lanes 4, 5, 7, 8, 11, 12, 14, and 15) in the presence of 2 mM EGTA (A) or 200 μM free calcium (B). The empty arrow indicates a contamination of GST from the recombinant syntaxin 1B preparation that interacts with glutathione–agarose beads. No nonspecific binding of SNARE proteins was observed by incubating them with GST-containing beads under the same conditions.