Structural and functional characterization of a putative polysaccharide deacetylase of the human parasite Encephalitozoon cuniculi

Jonathan E. Urch, Ramon Hurtado-Guerrero, Damien Brosson, Zhanliang Liu, Vincent G. H. Eijsink, Catherine Texier, Daan M. F. van Aalten

    Research output: Contribution to journalArticlepeer-review

    23 Citations (Scopus)


    The microsporidian Encephalitozoon cuniculi is an intracellular eukaryotic parasite considered to be an emerging opportunistic human pathogen. The infectious stage of this parasite is a unicellular spore that is surrounded by a chitin containing endospore layer and an external proteinaceous exospore. A putative chitin deacetylase ( ECU11_0510) localizes to the interface between the plasma membrane and the endospore. Chitin deacetylases are family 4 carbohydrate esterases in the CAZY classification, and several bacterial members of this family are involved in evading lysis by host glycosidases, through partial de-N-acetylation of cell wall peptidoglycan. Similarly, ECU11_0510 could be important for E. cuniculi survival in the host, by protecting the chitin layer from hydrolysis by human chitinases. Here, we describe the biochemical, structural, and glycan binding properties of the protein. Enzymatic analyses showed that the putative deacetylase is unable to deacetylate chitooligosaccharides or crystalline beta-chitin. Furthermore, carbohydrate microarray analysis revealed that the protein bound neither chitooligosaccharides nor any of a wide range of other glycans or chitin. The high resolution crystal structure revealed dramatic rearrangements in the positions of catalytic and substrate binding residues, which explain the loss of deacetylase activity, adding to the unusual structural plasticity observed in other members of this esterase family. Thus, it appears that the ECU11_0510 protein is not a carbohydrate deacetylase and may fulfill an as yet undiscovered role in the E. cuniculi parasite.

    Original languageEnglish
    Pages (from-to)1197-1209
    Number of pages13
    JournalProtein Science
    Issue number6
    Early online date14 Apr 2009
    Publication statusPublished - Jun 2009


    • Cell wall
    • Chitin
    • Peptidoglycan
    • Deacetylase
    • Protein structure
    • Glycobiology
    • Carbohydrates
    • N-acetylglucosamine deacetylase
    • Microsporidian spore wall
    • Chitin deacetylase
    • Serratia marcescens
    • Colletotrichum lindemuthianum
    • Intestinal microsporidiosis
    • Streptococcus pneumoniae
    • Virulence factor
    • Genome sequence
    • Mucor rouxii


    Dive into the research topics of 'Structural and functional characterization of a putative polysaccharide deacetylase of the human parasite Encephalitozoon cuniculi'. Together they form a unique fingerprint.

    Cite this