CATH Classification

Domain Context

CATH Clusters

Superfamily Chondroitin AC/alginate lyase
Functional Family

Enzyme Information

4.2.2.21
Chondroitin-sulfate-ABC exolyase.
based on mapping to UniProt C5G6D7
Exolytic removal of Delta(4)-unsaturated disaccharide residues from the non-reducing ends of both polymeric chondroitin/dermatan sulfates and their oligosaccharide fragments.
-!- 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. -!- The related enzyme EC 4.2.2.20 has the same substrate specificity but produces a mixture of oligosaccharides of different sizes that are ultimately degraded to tetra- and disaccharides. -!- Both enzymes act by the removal of a relatively acidic C-5 proton of the uronic acid followed by the elimination of a 4-linked hexosamine, resulting in the formation of an unsaturated C4-C5 bond on the hexuronic acid moiety of the products. -!- Formerly EC 4.2.2.4 and EC 4.2.99.6.

UniProtKB Entries (1)

C5G6D7
CABC2_BACT4
Bacteroides thetaiotaomicron
Chondroitin sulfate ABC exolyase

PDB Structure

PDB 2Q1F
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
Composite active site of chondroitin lyase ABC accepting both epimers of uronic acid.
Shaya, D., Hahn, B.S., Bjerkan, T.M., Kim, W.S., Park, N.Y., Sim, J.S., Kim, Y.S., Cygler, M.
Glycobiology