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:9282737). Pseudopilin (pilin-like) protein that polymerizes to form the pseudopilus. Further polymerization triggers pseudopilus growth (PubMed:16012171). Type II pseudopilus confers increased bacterial adhesive capabilities (PubMed:12700254). 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 (PubMed:16012171). Interacts with pseudopilin tip ternary complex made of XcpX, XcpU, XcpV and XcpW (PubMed:16012171). Interacts with PilA (PubMed:9282737). Translocation to the cell inner membrane is independent of the presence of other Xcp components but depends on a functional Sec apparatus. 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. Truncated N-terminus.