Part of the H2 type VI secretion system (H2-T6SS) specialized secretion system, which delivers several virulence factors in both prokaryotic and eukaryotic cells during infection (PubMed:26037124). May form the spike at the tip of the elongating tube formed by haemolysin co-regulated protein 2a/Hcp2a. In turn, may allow the delivery of the Tle4 antibacterial toxin to target cells where it exerts its toxicity (Probable). Promotes also the release of VgrG2b toxin to the host cell (PubMed:26037124). Deletion leads to a 75% loss of internalization of P.aeruginosa into host cell. Belongs to the VgrG protein family.