4dny

Structural highlights

Function

STCE_ECO57 Virulence factor that contributes to intimate adherence of enterohemorrhagic E.coli (EHEC) O157:H7 to host cells. Is able to cleave the secreted human mucin 7 (MUC7) and the glycoprotein 340 (DMBT1/GP340). Also cleaves human C1 inhibitor (SERPING1), a regulator of multiple inflammatory pathways, and binds and localizes it to bacterial and host cell surfaces, protecting them from complement-mediated lysis. Therefore, the current model proposes two roles for StcE during infection: it acts first as a mucinase, allowing passage of EHEC through the oral cavity by cleaving the salivary glycoproteins that are responsible for bacterial aggregation. Similarly, in the colon, StcE cleaves the glycoproteins that protect the intestinal epithelial surface, allowing EHEC to come into close contact with host cell membranes. Secondly, it acts as an anti-inflammatory agent by localizing SERPING1 to cell membranes.^{[1] [2] [3] [4]}

References

1. ↑ Grys TE, Siegel MB, Lathem WW, Welch RA. The StcE protease contributes to intimate adherence of enterohemorrhagic Escherichia coli O157:H7 to host cells. Infect Immun. 2005 Mar;73(3):1295-303. PMID:15731026 doi:http://dx.doi.org/10.1128/IAI.73.3.1295-1303.2005
2. ↑ Lathem WW, Grys TE, Witowski SE, Torres AG, Kaper JB, Tarr PI, Welch RA. StcE, a metalloprotease secreted by Escherichia coli O157:H7, specifically cleaves C1 esterase inhibitor. Mol Microbiol. 2002 Jul;45(2):277-88. PMID:12123444
3. ↑ Lathem WW, Bergsbaken T, Welch RA. Potentiation of C1 esterase inhibitor by StcE, a metalloprotease secreted by Escherichia coli O157:H7. J Exp Med. 2004 Apr 19;199(8):1077-87. PMID:15096536 doi:http://dx.doi.org/10.1084/jem.20030255
4. ↑ Grys TE, Walters LL, Welch RA. Characterization of the StcE protease activity of Escherichia coli O157:H7. J Bacteriol. 2006 Jul;188(13):4646-53. PMID:16788173 doi:http://dx.doi.org/10.1128/JB.01806-05