Toll-like receptor 2-activating lipoprotein IlpA from Vibrio vulnificus and similar lipoproteins; the type 2 periplasmic binding protein fold.
This group includes the IlpA protein which has both structural and sequential homology to the MetQ family of substrate-binding protein, and thus belongs to the type 2 periplasmic binding fold protein superfamily (PBP2). The PBP2 proteins are typically comprised of two globular subdomains connected by a flexible hinge and bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap. The majority of PBP2 proteins function in the uptake of small soluble substrates in eubacteria and archaea.