Sec18 supports membrane fusion by promoting Sec17 membrane association

Abstract

Sec18, bound at a distance from membranes, lowers the Sec17 needed for fusion. To do this, Sec18 complexes with several Sec17 molecules, allowing Sec17 to bind membranes through its N-terminal apolar loop. Membrane-bound Sec17 engages SNAREs to directly promote fusion, bypassing the need for complete SNARE zippering.