Figure 1.

HOPS complex inhibits fusion when the SNARE 0-layer is altered. Vacuoles from either BJ3505 and DKY6281 (A) or RFY1 and RFY2 (bearing Nyv1^R192Qp) (B) were assayed for fusion under standard ATP-free conditions (see Materials and Methods). Either wild-type Vam7p (squares) or mutant Vam7^Q283Rp (circles) was added at the indicated concentrations, either in the absence (closed symbols) or presence (open symbols) of 15.8 nM purified HOPS complex. Results are the mean of three independent experiments ± SD.