Role of Ca²⁺-binding sites in N-terminal or central portions of SiiE.

<p>A) Schematic overview of various mutant forms of SiiE with D/S exchanges in BIg2, BIg40 or BIg1-5 for deletion of 2 (Δ2) or 10 (Δ10) Ca²⁺-binding sites. B) Western blot for analyses of synthesis of mutant forms of SiiE. C) Amounts of retained SiiE after 3.5 h and 6 h of subculture. D) Secreted SiiE after 3.5 h and 6 h of subculture. E) SiiE-dependent invasion of polarized epithelial MDCK cells. Analyses of synthesis, surface retention and secretion and SiiE-dependent invasion of polarized cells were performed as described for <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1006418#ppat.1006418.g002" target="_blank">Fig 2</a>.