Glucoamylase (GA) (EC 18.104.22.168) is an enzyme that catalyzes the release of D-glucose from the non-reducing ends of starch and other oligo- or
polysaccharides. Extensive studies of fungal GA have shown [1,E1] that three
closely clustered acidic residues play a role in the catalytic mechanism of
GA. The region that includes these residues is also conserved in a recently
sequenced bacterial GA . We used this region as a signature pattern.
These proteins belong to family 15 in the classification of glycosyl
A GA from Schwanniomyces occidentalis is not a member of this family
but belongs to family 31 (see <PDOC00120>).
July 1998 / Text revised.
PROSITE method (with tools and information) covered by this documentation:
Sierks M.R., Ford C., Reilly P.J., Svensson B.
Catalytic mechanism of fungal glucoamylase as defined by mutagenesis of Asp176, Glu179 and Glu180 in the enzyme from Aspergillus awamori.
PROSITE is copyright. It is produced by the SIB Swiss Institute
Bioinformatics. There are no restrictions on its use by non-profit
institutions as long as its content is in no way modified. Usage by and
for commercial entities requires a license agreement. For information
about the licensing scheme send an email to
or see: prosite_license.html.