A short helix in the C-terminal region of LolA is important for the specific membrane localization of lipoproteins

The structures of a lipoprotein carrier, LolA, and a lipoprotein receptor, LolB, are similar except for an extra C-terminal loop containing a 310 helix and β-strand 12 in LolA. Lipoprotein release was significantly reduced when β-12 was deleted. Deletion of the 310 helix also inhibited the lipoprotein release. Furthermore, lipoproteins were non-specifically localized to membranes when LolA lacked the 310 helix. Thus, the membrane localization of lipoproteins with the LolA derivative lacking the 310 helix was independent of LolB whereas LolB was essential for the outer membrane localization of lipoproteins with the wild-type LolA.