Required for vesicle-mediated transport. Involved in endocytosis and endosome-endosome fusion. May be required for transport from the endoplasmic reticulum to the Golgi stack, and for the fusion of transport vesicles within the Golgi cisternae. Required for cell polarity, locomotion and chemotaxis. ATP + H2O = ADP + H(+) + phosphate Binds 1 Mg(2+) ion per subunit. Interacts with syn7A, snpA and snpC. Expressed in relatively constant amounts throughout the entire differentiation cycle. Belongs to the AAA ATPase family.