A new group of glycoside hydrolase family 13 α-amylases with an aberrant catalytic triad

• DOI: 10.1038/srep44230
• Publication Date: 2017-03-13T10:27:39Z
• Authors: Fean D. Sarian; Štefan Janeček; Tjaard Pijning; Ihsanawati; Zeily Nurachman; Ocky K. Radjasa; Lubbert Dijkhuizen; Dessy Natalia; Marc J. E. C. van...
• Keywords: Catalytic triad; Hydrolase; Aspartic acid; Glutamic acid; Residue (chemistry)

Abstract α-Amylases are glycoside hydrolase enzymes that act on the α(1→4) glycosidic linkages in glycogen, starch, and related α-glucans, ubiquitously present Nature. Most α-amylases have been classified family 13 with a typical (β/α) 8 -barrel containing two aspartic acid one glutamic residue play an essential role catalysis. An atypical α-amylase (BmaN1) only of three invariant catalytic residues was isolated from Bacillus megaterium strain NL3, bacterial isolate sea anemone Kakaban landlocked marine lake, Derawan Island, Indonesia. In BmaN1 third residue, acts as transition state stabilizer, replaced by histidine. Three-dimensional structure modeling amino sequence confirmed aberrant triad. Glucose maltose were found products action novel soluble demonstrating it is active spite peculiar This part group all this triad, consisting acid, Phylogenetic analysis showed comprises new subfamily 13.