Structural highlights
Function
[F17GG_ECOLX] Essential fimbrial adhesion factor that mediates binding to N-acetylglucosamine-containing receptors in the host intestinal microvilli, leading to colonization of the intestinal tissue, and diarrhea or septicemia. Also confers adhesiveness to laminin and basement membranes. May be involved in the initiation of polymerization of fimbrillin monomers during fimbrial filament biogenesis.[1] [2]
Publication Abstract from PubMed
GafD in Escherichia coli G (F17) fimbriae is associated with diarrheal disease, and the structure of the ligand-binding domain, GafD1-178, has been determined at 1.7A resolution in the presence of the receptor sugar N-acetyl-D-glucosamine. The overall fold is a beta-barrel jelly-roll fold. The ligand-binding site was identified and localized to the side of the molecule. Receptor binding is mediated by side-chain as well main-chain interactions. Ala43-Asn44, Ser116-Thr117 form the sugar acetamide specificity pocket, while Asp88 confers tight binding and Trp109 appears to position the ligand. There is a disulfide bond that rigidifies the acetamide specificity pocket. The three fimbrial lectins, GafD, FimH and PapG share similar beta-barrel folds but display different ligand-binding regions and disulfide-bond patterns. We suggest an evolutionary path for the evolution of the very diverse fimbrial lectins from a common ancestral fold.
The structural basis of receptor-binding by Escherichia coli associated with diarrhea and septicemia.,Merckel MC, Tanskanen J, Edelman S, Westerlund-Wikstrom B, Korhonen TK, Goldman A J Mol Biol. 2003 Aug 22;331(4):897-905. PMID:12909017[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Saarela S, Taira S, Nurmiaho-Lassila EL, Makkonen A, Rhen M. The Escherichia coli G-fimbrial lectin protein participates both in fimbrial biogenesis and in recognition of the receptor N-acetyl-D-glucosamine. J Bacteriol. 1995 Mar;177(6):1477-84. PMID:7883703
- ↑ Saarela S, Westerlund-Wikstrom B, Rhen M, Korhonen TK. The GafD protein of the G (F17) fimbrial complex confers adhesiveness of Escherichia coli to laminin. Infect Immun. 1996 Jul;64(7):2857-60. PMID:8698525
- ↑ Merckel MC, Tanskanen J, Edelman S, Westerlund-Wikstrom B, Korhonen TK, Goldman A. The structural basis of receptor-binding by Escherichia coli associated with diarrhea and septicemia. J Mol Biol. 2003 Aug 22;331(4):897-905. PMID:12909017
