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 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 [2],[3] is found at the A/B-domain 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
- ↑ Machius M, Declerck N, Huber R, Wiegand G. Activation of Bacillus licheniformis alpha-amylase through a disorder-->order transition of the substrate-binding site mediated by a calcium-sodium-calcium metal triad. Structure. 1998 Mar 15;6(3):281-92. PMID:9551551
- ↑ Brzozowski AM, Lawson DM, Turkenburg JP, Bisgaard-Frantzen H, Svendsen A, Borchert TV, Dauter Z, Wilson KS, Davies GJ. Structural analysis of a chimeric bacterial alpha-amylase. High-resolution analysis of native and ligand complexes. Biochemistry. 2000 Aug 8;39(31):9099-107. PMID:10924103
