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CATH Superfamily 2.70.98.10

The name of this superfamily has been modified since the most recent official CATH+ release (v4_2_0). At the point of the last release, this superfamily was: waiting to be named.

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 5034: Chondroitin sulfate ABC endolyase

There are 1 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
Chondroitin-sulfate-ABC endolyase. [EC: 4.2.2.20]
Endolytic cleavage of (1->4)-beta-galactosaminic bonds between N-acetylgalactosamine and either D-glucuronic acid or L-iduronic acid to produce a mixture of Delta(4)-unsaturated oligosaccharides of different sizes that are ultimately degraded to Delta(4)-unsaturated tetra- and disaccharides.
  • Degrades a variety of glycosaminoglycans of the chondroitin-sulfate- and dermatan-sulfate type.
  • Chondroitin sulfate, chondroitin-sulfate proteoglycan and dermatan sulfate are the best substrates but the enzyme can also act on hyaluronan at a much lower rate.
  • Keratan sulfate, heparan sulfate and heparin are not substrates.
  • In general, chondroitin sulfate (CS) and dermatan sulfate (DS) chains comprise a linkage region, a chain cap and a repeat region.
  • The repeat region of CS is a repeating disaccharide of glucuronic acid (GlcA) and N-acetylgalactosamine (GalNAc) [-4)GlcA(beta-1- 3)GalNAc(beta-1-](n), which may be O-sulfated on the C-4 and/or C-6 of GalNAc and C-2 of GlcA.
  • GlcA residues of CS may be epimerized to iduronic acid (IdoA) forming the repeating disaccharide [-4)IdoA(alpha-1-3)GalNAc(beta-1-](n) of DS.
  • Both the concentrations and locations of sulfate-ester substituents vary with glucosaminoglycan source.
  • The related enzyme EC 4.2.2.21 has the same substrate specificity but removes disaccharide residues from the non-reducing ends of both polymeric chondroitin sulfates and their oligosaccharide fragments produced by EC 4.2.2.20.
  • Formerly EC 4.2.2.4 and EC 4.2.99.6.
 1 P59807
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