This domain is found in TP0453, a lipoprotein associated with the inner leaflet of the outer membrane of Treponema pallidum. This protein consists of an alpha/beta/alpha-fold and includes five stably folded amphipathic helices and may function as a carrier of lipids, glycolipids, and/or derivatives during the biogenesis of the outer membrane [1].

1: The transition from closed to open conformation of Treponema pallidum outer membrane-associated lipoprotein TP0453 involves membrane sensing and integration by two amphipathic helices. Luthra A, Zhu G, Desrosiers DC, Eggers CH, Mulay V, Anand A, McArthur FA, Romano FB, Caimano MJ, Heuck AP, Malkowski MG, Radolf JD; J Biol Chem. 2011;286:41656-41668. PMID:21965687