Sesquiterpene synthase that catalyzes the conversion of farnesyl diphosphate to (-)-5-epi-eremophilene. (2E,6E)-farnesyl diphosphate = (-)-5-epi-eremophilene + diphosphate Binds 3 Mg(2+) ions per subunit. kcat is 2.09 sec(-1) with farnesyl diphosphate as substrate. Secondary metabolite biosynthesis; terpenoid biosynthesis. Monomer. Highly expressed in leaves and at lower levels in flowers. Induced by ethylene. The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family. Tpsa subfamily.