PROSITE documentation PDOC00120
Glycosyl hydrolases family 31 signatures


It has been shown [1,2,3,E1] that the following glycosyl hydrolases can be, on the basis of sequence similarities, classified into a single family:

  • Lysosomal α-glucosidase (EC (acid maltase) is a vertebrate glycosidase active at low pH, which hydrolyzes α(1->4) and α(1->6) linkages in glycogen, maltose, and isomaltose.
  • α-glucosidase (EC from the yeast Candida tsukunbaensis.
  • α-glucosidase (EC (gene malA) from the archebacteria Sulfolobus solfataricus.
  • Intestinal sucrase-isomaltase (EC / EC is a vertebrate membrane-bound, multifunctional enzyme complex which hydrolyzes sucrose, maltose and isomaltose. The sucrase and isomaltase domains of the enzyme are homologous (41% of amino acid identity) and have most probably evolved by duplication.
  • Glucoamylase 1 (EC (glucan 1,4-α-glucosidase) from various fungal species.
  • Yeast hypothetical protein YBR229c.
  • Fission yeast hypothetical protein SpAC30D11.01c.

An aspartic acid has been implicated [4] in the catalytic activity of sucrase, isomaltase, and lysosomal α-glucosidase. The region around this active residue is highly conserved and can be used as a signature pattern. We have used a second region, which contains two conserved cysteines, as an additional signature pattern.

Expert(s) to contact by email:

Henrissat B.

Last update:

April 2006 / Pattern revised.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

GLYCOSYL_HYDROL_F31_1, PS00129; Glycosyl hydrolases family 31 active site  (PATTERN)

GLYCOSYL_HYDROL_F31_2, PS00707; Glycosyl hydrolases family 31 signature 2  (PATTERN)


1AuthorsHenrissat B.
TitleA classification of glycosyl hydrolases based on amino acid sequence similarities.
SourceBiochem. J. 280:309-316(1991).
PubMed ID1747104

2AuthorsKinsella B.T. Hogan S. Larkin A. Cantwell B.A.
TitlePrimary structure and processing of the Candida tsukubaensis alpha-glucosidase. Homology with the rabbit intestinal sucrase-isomaltase complex and human lysosomal alpha-glucosidase.
SourceEur. J. Biochem. 202:657-664(1991).
PubMed ID1761061

3AuthorsNaim H.Y. Niermann T. Kleinhans U. Hollenberg C.P. Strasser A.W.M.
TitleStriking structural and functional similarities suggest that intestinal sucrase-isomaltase, human lysosomal alpha-glucosidase and Schwanniomyces occidentalis glucoamylase are derived from a common ancestral gene.
SourceFEBS Lett. 294:109-112(1991).
PubMed ID1743281

4AuthorsHermans M.M.P. Kroos M.A. van Beeumen J. Oostra B.A. Reuser A.J.
TitleHuman lysosomal alpha-glucosidase. Characterization of the catalytic site.
SourceJ. Biol. Chem. 266:13507-13512(1991).
PubMed ID1856189


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