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CATH Superfamily 2.160.20.10

Single-stranded right-handed beta-helix, Pectin lyase-like

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 named:

"
Single-stranded right-handed beta-helix, Pectin lyase-like
".

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 22171: Chondroitinase-B

There are 2 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 B lyase. [EC: 4.2.2.19]
Eliminative cleavage of dermatan sulfate containing (1->4)-beta-D- hexosaminyl and (1->3)-beta-D-glucurosonyl or (1->3)-alpha-L-iduronosyl linkages to disaccharides containing 4-deoxy-beta-D-gluc-4-enuronosyl groups to yield a 4,5-unsaturated dermatan-sulfate disaccharide (Delta- UA-GalNAc-4S).
  • This is the only lyase that is known to be specific for dermatan sulfate as substrate.
  • The minimum substrate length required for catalysis is a tetrasaccharide.
  • 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.
 2 Q46079 Q46079
Mannuronate-specific alginate lyase. [EC: 4.2.2.3]
Eliminative cleavage of alginate to give oligosaccharides with 4-deoxy- alpha-L-erythro-hex-4-enuronosyl groups at their non-reducing ends and beta-D-mannuronate at their reducing end.
  • The enzyme catalyzes the degradation of alginate by a beta- elimination reaction.
  • It cleaves the (1->4) bond between beta-D-mannuronate and either alpha-L-guluronate or beta-D-mannuronate, generating oligosaccharides with 4-deoxy-alpha-L-erythro-hex-4-enuronosyl groups at their non- reducing ends and beta-D-mannuronate at the reducing end.
  • Depending on the composition of the substrate, the enzyme produces oligosaccharides ranging from two to four residues, with preference for shorter products.
  • Cf. EC 4.2.2.11.
  • Formerly EC 4.2.99.4.
 2 Q06365 Q06365
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