2yn3

Publication Abstract from PubMed

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 Ca(2+)-binding sites. Sequence homology considerations suggest that full-length SiiE interacts with more than 100 Ca(2+) ions. Molecular dynamics simulations and single-molecule imaging indicate that Ca(2+) 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.

Structural Insight into the Giant Ca(2+)-Binding Adhesin SiiE: Implications for the Adhesion of Salmonella enterica to Polarized Epithelial Cells.,Griessl MH, Schmid B, Kassler K, Braunsmann C, Ritter R, Barlag B, Stierhof YD, Sturm KU, Danzer C, Wagner C, Schaffer TE, Sticht H, Hensel M, Muller YA Structure. 2013 May 7;21(5):741-52. doi: 10.1016/j.str.2013.02.020. Epub 2013 Apr, 4. PMID:23562396^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.