<p>O-Glycosyl hydrolases <db_xref db="EC" dbkey="3.2.1."/> are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of 85 different families [<cite idref="PUB00004870"/>, <cite idref="PUB00005266"/>]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site.</p><p>Glycoside hydrolase family 26 <db_xref db="CAZY" dbkey="GH26"/> encompasses mainly mannan endo-1,4-beta-mannosidases (<db_xref db="EC" dbkey="3.2.1.78"/>). Mannan endo-1,4-beta-mannosidase hydrolyses mannan and galactomannan, butdisplays little activity towards other plant cell wall polysaccharides [<cite idref="PUB00000537"/>]. The enzyme randomly hydrolyses 1,4-beta-D-linkages in mannans, galacto-mannans, glucomannans and galactoglucomannans.</p><p> This entry also incoporates the enzyme Endogluconase H <db_xref db="EC" dbkey="3.2.1.4"/> catalyzes the endohydrolysis of 1,4-beta-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans. </p> Endoglucanase H/Glycosyl hydrolase family 26