F17G/GafD
The F17-G (GafD) adhesin at the tip of flexible F17 fimbriae of enterotoxigenic Escherichia coli mediates binding to N-acetyl-β-D-glucosamine-presenting receptors on the microvilli of the intestinal epithelium of ruminants, leading to diarrhea or septicaemia. F17-G belong to two-domain adhesins (TDA)s consisting of a pilin domain and a lectin domain, both having an Ig-fold joined via a short interdomain linker[1][2]. Related adhesins have been characterized in enteropathogenic E. coli ( FedF on F18 fimbriae[3] and CfaE on CFA/I pili[4]) ) and uropathogenic ones (FimH on type 1 fimbriae[5] and PapG on P-pili[6]). Fimbrial adhesins from other organisms, such as CupB6 from Pseudomonas aeruginosa are also investigated. All share the immunoglobulin-like fold of the two structural components, despite lack of any sequence identity and diversity in carbohydrate specificity and binding site, and the corresponding pili are assembled by the chaperone-usher pathway[7][8]. The paradigm is unique among TAD for his specificity toward GlcNAc. The binding site is located laterally and not at the tip of the pili, therefore the long and flexible F17 fimbriae could intrude between the microvilli of the epithelium, with the binding site of the lectin domain interacting laterally with GlcNAc-containing receptors. Five naturally occurring variants, differing in 1-18 amino acids of the adhesion domain have been identified[9].
CFG Participating Investigators contributing to the understanding of this paradigm
This is an emerging field of investigation and contributions arose from a small number of CFG Participating Investigators (PIs). These include: Esther Bullit, Eric Cox, Anne Imberty, Remy Loris, James Nataro
Progress toward understanding this GBP paradigm
Carbohydrate ligands
Cellular expression
Structure
Biological roles of GBP-ligand interaction
CFG resources used in investigations
The best examples of CFG contributions to this paradigm are described below, with links to specific data sets. For a complete list of CFG data and resources relating to this paradigm, see the CFG database search results for fimbriae and pili.
Glycan profiling
Glycogene microarray
Knockout mouse lines
Glycan array
F17G adhesins have been screened for their glycan specificity: http://www.functionalglycomics.org/glycomics/search/jsp/landing.jsp?query=F17G&maxresults=20
The specificity of some of the other fimbrial tip adhesins was determined by CFG glycan array analysis (P. gingivalis fimbriae, E. coli FedF adhesin, E. coli CfaE adhesin from CFA/I pili)
Related GBPs
FedF, CfaE, FimH, PapG, CupB6
References
- ↑ Buts, L., Bouckaert, J., De Gents, E., Loris, R., Oscarson, S., Lahmann, M., Messens, J., Brosens, E., Wyns, L. & De Greve, H. (2003). The fimbrial adhesin F17-G of enterotoxigenic Escherichia coli has an immunoglobulin-like lectin domain that binds N-acetylglucosamine. Mol. Microb. 49, 705-715.
- ↑ Merckel, M. C., Tanskanen, J., Edelman, S., Westerlund-Wilkström, B., Korhonen, T. K. & Goldman, A. (2003). The structural basis of receptor-binding by Escherichia coli associaed with diarrhea and septicemia. J. Mol. Biol. 331, 897-905.
- ↑ Coddens, A., Diswall, M., Angstrom, J., Breimer, M. E., Goddeeris, B., Cox, E. & Teneberg, S. (2009). Recognition of blood group ABH type 1 determinants by the FedF adhesin of F18-fimbriated Escherichia coli. J Biol Chem 284, 9713-26.
- ↑ Poole, S. T., McVeigh, A. L., Anantha, R. P., Lee, L. H., Akay, Y. M., Pontzer, E. A., Scott, D. A., Bullitt, E. & Savarino, S. J. (2007). Donor strand complementation governs intersubunit interaction of fimbriae of the alternate chaperone pathway. Mol Microbiol 63, 1372-84.
- ↑ Bouckaert, J., Berglund, J., Schembri, M., De Gents, E., Cools, L., Wuhrer, M., Hung, C.-S., Pinkner, J., Slättegard, R., Savialov, A., Choudhury, D., Langermann, S., Hultgren, S. J., Wyns, L., Klemm, P., Oscarson, S., Knight, S. D. & De Greve, H. (2005). Receptor binding studies disclose a novel class of high-affinity inhibitors of the Escherichia coli FimH adhesin. Mol. Microb. 55, 441-455.
- ↑ Dodson, K. W., Pinkner, J. S., Rose, T., Magnusson, G., Hultgren, S. J. & Waksman, G. (2001). Structural basis of the interaction of the pyelonephritic E. coli adhesin to ist human kideny receptor. Cell 105, 733-743.
- ↑ De Greve, H., Wyns, L. & Bouckaert, J. (2007). Combining sites of bacterial fimbriae. Curr Opin Struct Biol 17, 506-12.
- ↑ Sauer, F. G., Barnhart, M., Choudhury, D., Knight, S. D., Waksman, G. & Hultgren, S. J. (2000). Chaperone-assisted pilus assembly and bacterial attachment. Curr Opin Struct Biol 10, 548-56.
- ↑ De Kerpel, M., Van Molle, I., Brys, L., Wyns, L., De Greve, H. & Bouckaert, J. (2006). N-terminal truncation enables crystallization of the receptor-binding domain of the FedF bacterial adhesin. Acta Crystallogr Sect F Struct Biol Cryst Commun 62, 1278-82.
Acknowledgements
The CFG is grateful to the following PIs for their contributions to this wiki page: Alisdair Boraston, Julie Bouckaert, Anne Imberty
