Core component of the type II secretion system required for the energy-dependent secretion of extracellular factors such as proteases and toxins from the periplasm (PubMed:8809775). Pseudopilin (pilin-like) protein that polymerizes to form the pseudopilus. Further polymerization triggers pseudopilus growth (PubMed:15491357). Type II secretion system is composed of four main components: the outer membrane complex, the inner membrane complex, the cytoplasmic secretion ATPase and the periplasm-spanning pseudopilus. Forms homomultimers. Cleaved by the prepilin peptidase. Methylated by prepilin peptidase at the amino group of the N-terminal phenylalanine once the leader sequence is cleaved. Belongs to the GSP G family.