Lactate dehydrogenase/glycoside hydrolase, family 4, C-terminal <p>This entry represents a structural motif found at the C-terminal of lactate dehydrogenase (<db_xref db="EC" dbkey="1.1.1.27"/>)and malate dehydrogenases (<db_xref db="EC" dbkey="1.1.1.37"/>), as well as at the C-terminal of family 4 glycoside hydrolases (<db_xref db="EC" dbkey="3.2.1"/>). These domains have an unusual fold consisting of segregated alpha-helical and beta-sheet regions, although they contain predominantly anti-parallel beta-sheets [<cite idref="PUB00025866"/>, <cite idref="PUB00027386"/>, <cite idref="PUB00029383"/>].</p> <p>L-lactate dehydrogenases are metabolic enzymes that catalyse the conversion of L-lactate to pyruvate, the last step in anaerobic glycolysis. L-lactate dehydrogenase is also found as a lens crystallin in bird and crocodile eyes. Malate dehydrogenases catalyse the interconversion of malate to oxaloacetate. The enzyme participates in the citric acid cycle.</p><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"/>, <cite idref="PUB00005672"/>]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site. Because the fold of proteins is better conserved than their sequences, some of the families can be grouped in 'clans'. Glycoside hydrolase family 4 <db_xref db="CAZY" dbkey="GH4"/>comprises enzymes with several known activities; 6-phospho-beta-glucosidase (<db_xref db="EC" dbkey="3.2.1.86"/>); 6-phospho-alpha-glucosidase (<db_xref db="EC" dbkey="3.2.1.122"/>); alpha-galactosidase (<db_xref db="EC" dbkey="3.2.1.22"/>).</p>