AF083: Glycoside hydrolase family 3

List allergens from this family:

Routes of exposure:
Include only IUIS approved allergens.

Biochemical properties

Glycoside hydrolase family 3 comprises enzymes with a number of known activities: β-glucosidase, β-xylosidase, N-acetyl-β-glucosaminidase, glucan-β-1,3-glucosidase, cellodextrinase, and exo-1,3-1,4-glucanase. These enzymes are two-domain globular proteins that are N-glycosylated at three sites [1].

Allergens from this family

Asp n 14, a xylanase from Aspergillus niger, which is used as a dough improver in the baking industry, was identified as an occupational allergen [2].



  1. Varghese JN, Hrmova M, Fincher GB:
    Three-dimensional structure of a barley beta-D-glucan exohydrolase, a family 3 glycosyl hydrolase.
    Structure 1999, 7, 179-90. [PubMed]
  2. Sander I, Raulf-Heimsoth M, Siethoff C, Lohaus C, Meyer HE, Baur X:
    Allergy to Aspergillus-derived enzymes in the baking industry: identification of beta-xylosidase from Aspergillus niger as a new allergen (Asp n 14).
    J Allergy Clin Immunol 1998, 102, 256-64. [PubMed]


Links to Pfam

Family-defining Pfam domains (at least one of these domains is present in each family member):

Pfam domain Pfam clan
PF00933 Glycosyl hydrolase family 3 N terminal domain CL0058 Tim barrel glycosyl hydrolase superfamily
PF01915 Glycosyl hydrolase family 3 C-terminal domain -

Additional Pfam domains found in some family members:

Pfam domain Pfam clan
PF14310 Fibronectin type III-like domain CL0159 Ig-like fold superfamily (E-set)

Links to Wikipedia


If you have updates or corrections for this entry, please contact the site administrator: .