The Vam7 N-domain stimulates SNARE-dependent dequenching in the presence of full-length Vam7p. (A) Incubations with Vam7tm. R-SNARE RPLs and 3Q-SNARE RPLs bearing Vam7tm were incubated with control buffer addition, 1.1 μM GST-Vam7(1-125)p, Factor Xa (10 μg/mL), or GST-Vam7(1-125)p that had been preincubated with Factor Xa. Reactions 1 to 4 used RPLs that bore phosphoinositides [PI3P and PI(4,5)P2]. (B) Incubations with WT Vam7p. R-SNARE RPLs and 3Q-SNARE RPLs bearing WT Vam7p were incubated with control buffer addition, with Sec17p (100 nM) and Sec18p (83 nM), or with 1.1 μM Vam7(1-125)p that had been preincubated with Factor Xa.