Probably responsible for the transport of L-galactonate from the periplasm across the inner membrane. Is essential for growth on L-galactonate as the sole carbon source. H(+)(in) + L-galactonate(in) = H(+)(out) + L-galactonate(out) Highly up-regulated during growth on L-galactonate. Cells lacking this gene fail to grow on L-galactonate as sole carbon source. Belongs to the major facilitator superfamily. Phthalate permease family.