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CATH Superfamily 3.20.20.80

Glycosidases

The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was named:

"
Glycosidases
".

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 16: Maltase-glucoamylase, intestinal

There are 5 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Alpha-glucosidase. [EC: 3.2.1.20]
Hydrolysis of terminal, non-reducing (1->4)-linked alpha-D-glucose residues with release of alpha-D-glucose.
  • Group of enzymes whose specificity is directed mainly toward the exohydrolysis of 1,4-alpha-glucosidic linkages, and that hydrolyze oligosaccharides rapidly, relative to polysaccharides, which are hydrolyzed relatively slowly, or not at all.
  • The intestinal enzyme also hydrolyzes polysaccharides, catalyzing the reactions of EC 3.2.1.3, and, more slowly, hydrolyzes 1,6-alpha-D- glucose links.
 39 A0A319B736 A0A319B736 A0A319B736 A0A319B736 A0A319B736 A0A319B736 A0A370BQT6 A0A370BQT6 A0A370BQT6 A0A370BQT6
(29 more...)
Sucrose alpha-glucosidase. [EC: 3.2.1.48]
Hydrolysis of sucrose and maltose by an alpha-D-glucosidase-type action.
  • Isolated from intestinal mucosa as a single polypeptide chain also displaying activity toward isomaltose (EC 3.2.1.10).
 4 P14410 P14410 P23739 P23739
Oligo-1,6-glucosidase. [EC: 3.2.1.10]
Hydrolysis of (1->6)-alpha-D-glucosidic linkages in some oligosaccharides produced from starch and glycogen by alpha-amylase, and in isomaltose.
  • This enzyme, like EC 3.2.1.33, can release an alpha-1->6-linked glucose, whereas the shortest chain that can be released by EC 3.2.1.41, EC 3.2.1.142 and EC 3.2.1.68 is maltose.
  • It also hydrolyzes isomaltulose (palatinose), isomaltotriose and panose, but has no action on glycogen or phosphorylase limit dextrin.
  • The enzyme from intestinal mucosa is a single polypeptide chain that also catalyzes the reaction of EC 3.2.1.48.
  • Differs from EC 3.2.1.33 in its preference for short-chain substrates and in its not requiring the 6-glucosylated residue to be at a branch point, i.e. linked at both C-1 and C-4.
 4 P14410 P14410 P23739 P23739
Glucan 1,4-alpha-glucosidase. [EC: 3.2.1.3]
Hydrolysis of terminal (1->4)-linked alpha-D-glucose residues successively from non-reducing ends of the chains with release of beta-D- glucose.
  • Most forms of the enzyme can rapidly hydrolyze 1,6-alpha-D-glucosidic bonds when the next bond in the sequence is 1,4, and some preparations of this enzyme hydrolyze 1,6- and 1,3-alpha-D-glucosidic bonds in other polysaccharides.
  • This entry covers all such enzymes acting on polysaccharides more rapidly than on oligosaccharides.
  • EC 3.2.1.20 from mammalian intestine can catalyze similar reactions.
 2 O43451 O43451
Alpha-D-xyloside xylohydrolase. [EC: 3.2.1.177]
Hydrolysis of terminal, non-reducing alpha-D-xylose residues with release of alpha-D-xylose.
  • The enzyme catalyzes hydrolysis of a terminal, unsubstituted xyloside at the extreme reducing end of a xylogluco-oligosaccharide.
  • Representative alpha-xylosidases from glycoside hydrolase family 31 utilize a two-step (double-displacement) mechanism involving a covalent glycosyl-enzyme intermediate, and retain the anomeric configuration of the product.
 2 F4J6T7 Q9S7Y7
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