Tip adhesin component of type P pili that binds preferentially to host cell glycosphingolipids such as globotriaosylceramide. Interacts with chaperone PapD. Assembly of the P pilus requires periplasmic chaperone PapD, in absence of the chaperone overexpression of this subunit is toxic, where the protein accumulates in the periplasm. PapD stimulates release of PapG from an inner membrane-associated form (where at least 1 disulfide bond can form) into the periplasm and also helps it achieve its correct digalactoside-binding conformation (PubMed:9351822). At the tip of P pili. Contains disulfide bonds (PubMed:9351822). Belongs to the adhesin PapG family.