Agirre, Jon orcid.org/0000-0002-1086-0253, Moroz, Olga, Meier, Sebastian et al. (6 more authors) (2019) The structure of the AliC GH13 α-amylase from Alicyclobacillus sp. reveals the accommodation of starch branching points in the α-amylase family. Acta crystallographica. Section D, Structural biology. pp. 1-7. ISSN 2059-7983
Abstract
α-Amylases are glycoside hydrolases that break the α-1,4 bonds in starch and related glycans. The degradation of starch is rendered difficult by the presence of varying degrees of α-1,6 branch points and their possible accommodation within the active centre of α-amylase enzymes. Given the myriad industrial uses for starch and thus also for α-amylase-catalysed starch degradation and modification, there is considerable interest in how different α-amylases might accommodate these branches, thus impacting on the potential processing of highly branched post-hydrolysis remnants (known as limit dextrins) and societal applications. Here, it was sought to probe the branch-point accommodation of the Alicyclobacillus sp. CAZy family GH13 α-amylase AliC, prompted by the observation of a molecule of glucose in a position that may represent a branch point in an acarbose complex solved at 2.1 Å resolution. Limit digest analysis by two-dimensional NMR using both pullulan (a regular linear polysaccharide of α-1,4, α-1,4, α-1,6 repeating trisaccharides) and amylopectin starch showed how the Alicyclobacillus sp. enzyme could accept α-1,6 branches in at least the -2, +1 and +2 subsites, consistent with the three-dimensional structures with glucosyl moieties in the +1 and +2 subsites and the solvent-exposure of the -2 subsite 6-hydroxyl group. Together, the work provides a rare insight into branch-point acceptance in these industrial catalysts.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | open access. |
Keywords: | AliC GH13 α-amylase,Alicyclobacillus,carbohydrate-active enzymes,glycoside hydrolases,pullulan,starch branching points |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 18 Jan 2019 11:50 |
Last Modified: | 16 Oct 2024 15:24 |
Published Version: | https://doi.org/10.1107/S2059798318014900 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1107/S2059798318014900 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:141278 |
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Description: The structure of the AliC GH13 a-amylase from Alicyclobacillus sp. reveals the accommodation of starch branching points in the a-amylase family