- Neisseria gonorrhoeae type IV pili undergo multisite, hierarchical modifications with phosphoethanolamine and phosphocholine requiring an enzyme structurally related to lipopolysaccharide phosphoethanolamine transferases. Aas, F.E., Egge-Jacobsen, W., Winther-Larsen, H.C., Løvold, C., Hitchen, P.G., Dell, A., Koomey, M. J. Biol. Chem. (2006)