Part of a type II secretion system (T2SS, formerly general secretion pathway, GSP) for the export of folded proteins across the outer membrane (Probable). Required for correct assembly of the type II secretion system-beta (T2SS-beta), for localization of GspD-beta to the cell outer membrane and for export of a labile enterotoxin by T2SS-beta (PubMed:22585966). Each AspS2 binds to 2 GspD2 subunits and may clamp the monomers together, stabilizing structure and accelerating its assembly (PubMed:29632366). Cryo-electron microscopy shows the complex forms a cylindrical channel with 15 GspD2 subunits, each of which interacts with its surroundingy AspS2 (GspS-beta). Protein can also be located in the cell inner membrane. Severely disrupts assembly and function of T2SS-beta, mislocalization of GspD-beta to the cell inner membrane. Encoded in a type II secretion system (T2SS-beta); this strain encodes 2 T2SS but only this one (beta) is expressed under standard laboratory conditions. Belongs to the GspS/AspS pilotin family.