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EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 1amy

E.C. namealpha-amylase
SpeciesHordeum vulgare (Barley)
E.C. Number (IntEnz)
CSA Homologues of 1amyThere are 273 Homologs
CSA Entries With UniProtID P04063
CSA Entries With EC Number
PDBe Entry 1amy
PDBSum Entry 1amy
MACiE Entry 1amy

Literature Report

IntroductionAlpha-amylase catalyses the hydrolysis of internal alpha-glucosidic linkages in starch and other related oligo- and polysaccharides. These enzymes are widespread among the higher plants, animals and micro-organisms. Cereal alpha-amylases play an important role in the production of beer and other alcoholic beverages.
MechansimThe mechanism has not been studied in great detail, but its structural and stereochemical similarity to lysozyme suggests it probably utilises a similar mechanism.
The mechanistic overview for lysozyme is as follows: The glycosidic oxygen is protonated by the acid catalyst and the nucleophilic assistance for the leaving group's departure is provided by the base. The resulting glycosyl enzyme is hydrolysed by a water molecule and this second nucleophilic substitution at the anomeric carbon generates a product with the same stereochemistry as the substrate.

Catalytic Sites for 1amy

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
AspA179203macie:sideChainLikely to be the 'general base', forming a covalent intermediate with the substrate.
GluA204228macie:sideChainLikely to be the general acid.
AspA289313macie:sideChainMay help to activate the nucleophilic water molecule.

Literature References

Kadziola A
Crystal and molecular structure of barley alpha-amylase.
J Mol Biol 1994 239 104-121
PubMed: 8196040
Davies G
Structures and mechanisms of glycosyl hydrolases.
Structure 1995 3 853-859
PubMed: 8535779