Polysaccharide Lyase Family 6Polysaccharide Lyase Family 6 is a family of beta-helical polysaccharide lyases. Members include alginate lyase (EC 126.96.36.199) and chondroitinase B (EC 188.8.131.52). Chondroitinase B is an enzyme that only cleaves the beta-(1,4)-linkage of dermatan sulfate (DS), leading to 4,5-unsaturated dermatan sulfate disaccharides as the product. DS is a highly sulfated, unbranched polysaccharide belonging to a family of glycosaminoglycans (GAGs) composed of alternating hexosamine (gluco- or galactosamine) and uronic acid (D-glucuronic or L-iduronic acid) moieties. DS contains alternating 1,4-beta-D-galactosamine (GalNac) and 1,3-alpha-L-iduronic acid units. The related chondroitin sulfate (CS) contains alternating GalNac and 1,3-beta-D-glucuronic acid units. Alginate lyases (known as either mannuronate (EC 184.108.40.206) or guluronate lyases (EC 220.127.116.11) catalyze the degradation of alginate, a copolymer of alpha-L-guluronate and its C5 epimer beta-D-mannuronate.