Download MendeleyMulti-site substrate binding and interplay in barley alpha-amylase 1
Nielsen, M.M., Seo, E.S., Bozonnet, S., Aghajari, N., Robert, X., Haser, R., Svensson, B.(2008) FEBS Lett 582: 2567-2571
- PubMed: 18588886
- DOI: https://doi.org/10.1016/j.febslet.2008.06.027
- Primary Citation of Related Structures:
3BSG - PubMed Abstract:
Certain starch hydrolases possess secondary carbohydrate binding sites outside of the active site, suggesting that multi-site substrate interactions are functionally significant. In barley alpha-amylase both Tyr380, situated on a remote non-catalytic domain, and Tyr105 in subsite -6 of the active site cleft are principal carbohydrate binding residues. The dual active site/secondary site mutants Y105A/Y380A and Y105A/Y380M show that each of Tyr380 and Tyr105 is important, albeit not essential for binding, degradation, and multiple attack on polysaccharides, while Tyr105 predominates in oligosaccharide hydrolysis. Additional delicate structure/function relationships of the secondary site are uncovered using Y380A/H395A, Y380A, and H395A AMY1 mutants.
Organizational Affiliation:
Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Lyngby, Denmark.
