PilW is a family of putative type IV pilus-assembly proteins. PilW is one of the component proteins of the pilus biogenesis process whereby pilus fibres are assembled in the periplasm, emerge onto the cell surface and are there stabilised, to allow bacterial attachment to host cells. PilW is an outer-membrane protein necessary for both the functionality of fibres and their stabilisation [1].

1: Type IV pilus biogenesis in Neisseria meningitidis: PilW is involved in a step occurring after pilus assembly, essential for fibre stability and function. Carbonnelle E, Helaine S, Prouvensier L, Nassif X, Pelicic V; Mol Microbiol. 2005;55:54-64. PMID:15612916