National Center for
4UZU: Three-dimensional Structure Of A Variant `termamyl-like' Geobacillus Stearothermophilus Alpha-amylase At 1.9 A Resolution
Three-dimensional structure of a variant `Termamyl-like' Geobacillus stearothermophilus alpha-amylase at 1.9 Å resolution
Acta Crystallogr F Struct Biol Commun (2015) 71 p.66-70
The enzyme-catalysed degradation of starch is central to many industrial processes, including sugar manufacture and first-generation biofuels. Classical biotechnological platforms involve steam explosion of starch followed by the action of endo-acting glycoside hydrolases termed alpha-amylases and then exo-acting alpha-glucosidases (glucoamylases) to yield glucose, which is subsequently processed. A key enzymatic player in this pipeline is the `Termamyl' class of bacterial alpha-amylases and designed/evolved variants thereof. Here, the three-dimensional structure of one such Termamyl alpha-amylase variant based upon the parent Geobacillus stearothermophilus alpha-amylase is presented. The structure has been solved at 1.9 A resolution, revealing the classical three-domain fold stabilized by Ca(2+) and a Ca(2+)-Na(+)-Ca(2+) triad. As expected, the structure is similar to the G. stearothermophilus alpha-amylase but with main-chain deviations of up to 3 A in some regions, reflecting both the mutations and differing crystal-packing environments.