Soluble Sed5 Habc domain can stimulate Sly1-dependent fusion in the absence of Sec17 and Sec18. These experiments are like the ones in Fig. 8, except that Sec17 and Sec18 were omitted. (A–F) At t = −6 min, R-SNARE RPLs and Q-SNARE RPLS were mixed with 1.5 µM Sly1 that had been preincubated with either soluble Sed5N-Habc (A, B, and E) or Sed5Habc (C, D, and F). At t = 0, the reactions were initiated by the addition of 3% PEG. Points show mean ± SEM of at least three independent experiments. Gray lines show least-squares fits of a second-order kinetic function. The experiments in A–C were done in parallel with the experiments in Fig. 8 and separately from the experiments in E and F.