A structural motif is the recognition site for a new family of bacterial protein O-glycosyltransferases

Marie Ève Charbonneau, Jean Philippe Côté, M. Florencia Haurat, Bela Reiz, Sébastien Crépin, Frédéric Berthiaume, Charles M. Dozois, Mario F. Feldman, Michael Mourez

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Summary: 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.

Original languageEnglish
Pages (from-to)894-907
Number of pages14
JournalMolecular Microbiology
Issue number5
StatePublished - Mar 2012


Dive into the research topics of 'A structural motif is the recognition site for a new family of bacterial protein O-glycosyltransferases'. Together they form a unique fingerprint.

Cite this