4q1q
Crystal structure of TibC-catalyzed hyper-glycosylated TibA55-350 fragment
Structural highlights
FunctionTIBA_ECOH1 Mediates both adhesion to and invasion of human intestine epithelial cells. Also mediates bacterial cell aggregation via intercellular TibA-TibA interaction. Enhances biofilm formation.[1] [2] Publication Abstract from PubMedAutotransporters deliver virulence factors to the bacterial surface by translocating an effector passenger domain through a membrane-anchored barrel structure. Although passenger domains are diverse, those found in enteric bacteria autotransporters, including AIDA-I in diffusely adhering Escherichia coli (DAEC) and TibA in enterotoxigenic E. coli, are commonly glycosylated. We show that AIDA-I is heptosylated within the bacterial cytoplasm by autotransporter adhesin heptosyltransferase (AAH) and its paralogue AAH2. AIDA-I heptosylation determines DAEC adhesion to host cells. AAH/AAH2 define a bacterial autotransporter heptosyltransferase (BAHT) family that contains ferric ion and adopts a dodecamer assembly. Structural analyses of the heptosylated TibA passenger domain reveal 35 heptose conjugates forming patterned and solenoid-like arrays on the surface of a beta helix. Additionally, CARC, the AIDA-like autotransporter from Citrobacter rodentium, is essential for colonization in mice and requires heptosylation by its cognate BAHT. Our study establishes a bacterial glycosylation system that regulates virulence and is essential for pathogenesis. An iron-containing dodecameric heptosyltransferase family modifies bacterial autotransporters in pathogenesis.,Lu Q, Yao Q, Xu Y, Li L, Li S, Liu Y, Gao W, Niu M, Sharon M, Ben-Nissan G, Zamyatina A, Liu X, Chen S, Shao F Cell Host Microbe. 2014 Sep 10;16(3):351-63. doi: 10.1016/j.chom.2014.08.008. PMID:25211077[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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