LIS - Legume Information System
Information about legume traits for crop improvement
GlycineMine
v5.1.0.3
Glycine data from LIS
v5.1.0.3
Glycine data from LIS
| Type | Family |
| Description | O-Glycosyl hydrolases ( ) 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 [ , ]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) website.Glycoside hydrolase family 14 comprises enzymes with only one known activity; beta-amylase ( ). A Glu residue has been proposed as a catalytic residue, but it is not known if it is the nucleophile or the proton donor. Beta-amylase [ , ] is an enzyme that hydrolyses 1,4-alpha-glucosidic linkages in starch-type polysaccharide substrates so as to remove successive maltose units from the non-reducing ends of the chains. Beta-amylase is present in certain bacteria as well as in plants.Three highly conserved sequence regions are found in all known beta-amylases. The first of these regions is located in the N-terminal section of the enzymes and contains an aspartate which is known to be involved in the catalytic mechanism [ ]. The second, located in a more central location, is centred around a glutamate which is also involved in the catalytic mechanism [].The 3D structure of a complex of soybean beta-amylase with an inhibitor (alpha-cyclodextrin) has been determined to 3.0A resolution by X-ray diffraction [ ]. The enzyme folds into large and small domains: the large domain has a (beta alpha)8 super-secondary structural core, while the smaller is formed from two long loops extending from the beta-3 and beta-4 strands of the (beta alpha)8 fold. The interface of the two domains, together with shorter loops from the (beta alpha)8 core, form a deep cleft, in which the inhibitor binds. Two maltose molecules also bind in the cleft, one sharing a binding site with alpha-cyclodextrin, and the other sitting more deeply in the cleft []. |
| Short Name | Glyco_hydro_14 |
