<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 11 <db_xref db="CAZY" dbkey="GH11"/> comprises enzymes with only one known activity, xylanase (<db_xref db="EC" dbkey="3.2.1.8"/>), while family 12 <db_xref db="CAZY" dbkey="GH12"/> comprises enzymes with two known activities, endoglucanase (<db_xref db="EC" dbkey="3.2.1.4"/>) and xyloglucan hydrolase. This entry represents the catalytic core of family 11 and 12 glycoside hydrolases, which assumes a beta-sandwich structure of complex topology, consisting of 12-14 beta-strands in two sheets.</p> Glycoside hydrolase, family 11/12, catalytic domain