Component of the exocyst complex involved in the docking of exocytic vesicles with fusion sites on the plasma membrane. The exocyst complex is composed of sec3/exoc1, sec5/exoc2, sec6/exoc3, sec8/exoc4, sec10/exoc5, sec15/exoc6, exo70/exoc7 and exo84/exoc8. Belongs to the SEC5 family.