Charbonneau, Marie-Ève; Côté, Jean-Philippe; Haurat, M. Florencia; Reiz, Bela; Crépin, Sébastien; Berthiaume, Frederic; Dozois, Charles M. 
ORCID: https://orcid.org/0000-0003-4832-3936; Feldman, Mario F. et Mourez, Michael
(2012).
A structural motif is the recognition site for a new family of bacterial protein O-glycosyltransferases
Molecular Microbiology
, vol. 83
, nº 5..
pp. 894-907.
DOI: 10.1111/j.1365-2958.2012.07973.x.
Résumé
The Escherichia coli Adhesin Involved in Diffuse Adherence (AIDA-I) is a multifunctional protein that belongs to the family of monomeric autotransporters. This adhesin can be glycosylated by the AIDA-associated heptosyltransferase (Aah). Glycosylation appears to be restricted to the extracellular domain of AIDA-I, which comprises imperfect repeats of a 19-amino-acid consensus sequence and is predicted to form a β-helix. Here, we show that Aah homologues can be found in many Gram-negative bacteria, including Citrobacter rodentium. We demonstrated that an AIDA-like protein is glycosylated in this species by the Aah homologue. We then investigated the substrate recognition mechanism of the E. coli Aah heptosyltransferase. We found that a peptide corresponding to one repeat of the 19-amino-acid consensus is sufficient for recognition and glycosylation by Aah. Mutagenesis studies suggested that, unexpectedly, Aah recognizes a structural motif typical of β-helices, but not a specific sequence. In agreement with this finding, we observed that the extracellular domain of the Bordetella pertussis pertactin, a β-helical polypeptide lacking the 19-amino-acid consensus sequence, could be glycosylated by Aah. Overall, our findings suggest that Aah represents the prototype of a new large family of bacterial protein O-glycosyltransferases that modify various substrates recognized through a structural motif.
| Type de document: | Article |
|---|---|
| Mots-clés libres: | - |
| Centre: | Centre INRS-Institut Armand Frappier |
| Date de dépôt: | 06 mars 2024 15:30 |
| Dernière modification: | 08 mars 2024 15:02 |
| URI: | https://espace.inrs.ca/id/eprint/13998 |
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