Members of this family adopt a structure consisting of an immunoglobulin-like beta-sandwich, with seven strands in two beta-sheets, arranged in a Greek-key topology. It forms part of the extracellular region of the protein, which can be expressed as a soluble protein (Inv497) that binds integrins and promotes subsequent uptake by cells when attached to bacteria [1].

1: Crystal structure of invasin: a bacterial integrin-binding protein. Hamburger ZA, Brown MS, Isberg RR, Bjorkman PJ; Science. 1999;286:291-295. PMID:10514372