2YN5

Structural insight into the giant calcium-binding adhesin SiiE: implications for the adhesion of Salmonella enterica to polarized epithelial cells

Summary for 2YN5

• Entry DOI: 10.2210/pdb2yn5/pdb
• Related: 2YN3
• Descriptor: PUTATIVE INNER MEMBRANE PROTEIN, CALCIUM ION (3 entities in total)
• Functional Keywords: membrane protein, big-domains adhesin
• Biological source: SALMONELLA ENTERICA SUBSP. ENTERICA SEROVAR TYPHIMURIUM
• Total number of polymer chains: 2
• Total formula weight: 60922.74

Authors

Griessl, M.H.,Schmid, B.,Kassler, K.,Braunsmann, C.,Ritter, R.,Barlag, B.,Sturm, K.U.,Danzer, C.,Wagner, C.,Schaeffer, T.E.,Sticht, H.,Hensel, M.,Muller, Y.A. (deposition date: 2012-10-12, release date: 2013-04-03, Last modification date: 2023-12-20)

Primary citation

Griessl, M.H.,Schmid, B.,Kassler, K.,Braunsmann, C.,Ritter, R.,Barlag, B.,Stierhof, Y.,Sturm, K.U.,Danzer, C.,Wagner, C.,Schaffer, T.E.,Sticht, H.,Hensel, M.,Muller, Y.A.
Structural Insight Into the Giant Ca(2+)-Binding Adhesin Siie: Implications for the Adhesion of Salmonella Enterica to Polarized Epithelial Cells.
Structure, 21:741-, 2013

PubMed Abstract: SiiE from Salmonella enterica is a giant 5,559-residue-long nonfimbrial adhesin that is secreted by a type 1 secretion system (T1SS) and initiates bacterial adhesion to polarized host cells. Structural insight has been gained into the 53 bacterial Ig-like (BIg) domains of SiiE, which account for 94% of the entire SiiE sequence. The crystal structure of a fragment comprising BIg domains 50 to 52 of SiiE reveals the BIg domain architecture and highlights two types of SiiE-specific Ca²⁺-binding sites. Sequence homology considerations suggest that full-length SiiE interacts with more than 100 Ca²⁺ ions. Molecular dynamics simulations and single-molecule imaging indicate that Ca²⁺ binding confers SiiE with a rigid 200 nm rod-like habitus that is required to reach out beyond the Salmonella lipopolysaccharide layer and to promote adhesion to host cells. The crystal structure suggests plausible routes for the establishment of the initial contact between Salmonella and host cells.

PubMed: 23562396
DOI: 10.1016/J.STR.2013.02.020

Experimental method

X-RAY DIFFRACTION (1.85 Å)