Structure of the AmyC GH13 alpha-amylase from Alicyclobacillus sp, reveals accommodation of starch branching points in the alpha-amylase family
Jon Agirre, Olga Moroz, Sebastian Meier, Jesper Brask, Astrid Munch, Tine Hoff, Carsten Andersen, Keith S. Wilsona and Gideon J. Davies [1]
Molecular Tour
The enzymatic degradation of starch has a myriad industrial applications. However, the branched nature of the polysaccharides that compose it poses problems, as branches have to be accommodated within an active centre best suited to linear polysaccharides. Alpha-amylases are glycoside hydrolases that break the α-1,4 bonds in starch and related glycans. The present work provides a rare insight into branch-point acceptance in these industrial catalysts.
The complex of AliC with acarbose was solved by molecular replacement, with two molecules of AliC in the asymmetric unit, at a resolution of 2.1 Å . The fold, as expected, is a canonical three-domain arrangement with the A, B and C domains defined approximately as A, residues 4–104 and 210–397, B, residues 105–209, and C, residues 398–484. A classical Ca2+–Na+– Ca2+ triad (Machius et al., 1998; Brzozowski et al., 2000) is found at the A/Bdomain interface.
References
- ↑ Agirre J, Moroz O, Meier S, Brask J, Munch A, Hoff T, Andersen C, Wilson KS, Davies GJ. The structure of the AliC GH13 alpha-amylase from Alicyclobacillus sp. reveals the accommodation of starch branching points in the alpha-amylase family. Acta Crystallogr D Struct Biol. 2019 Jan 1;75(Pt 1):1-7. doi:, 10.1107/S2059798318014900. Epub 2019 Jan 4. PMID:30644839 doi:http://dx.doi.org/10.1107/S2059798318014900
