title: Three-dimensional structure of a variant `Termamyl-like' Geobacillus stearothermophilus α-amylase at 1.9 Å resolution.
abstract: 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 α-amylases and then exo-acting α-glucosidases (glucoamylases) to yield glucose, which is subsequently processed. A key enzymatic player in this pipeline is the `Termamyl' class of bacterial α-amylases and designed/evolved variants thereof. Here, the three-dimensional structure of one such Termamyl α-amylase variant based upon the parent Geobacillus stearothermophilus α-amylase is presented. The structure has been solved at 1.9 Å resolution, revealing the classical three-domain fold stabilized by Ca2+ and a Ca2+-Na+-Ca2+ triad. As expected, the structure is similar to the G. stearothermophilus α-amylase but with main-chain deviations of up to 3 Å in some regions, reflecting both the mutations and differing crystal-packing environments.
authors.affiliation: York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England.
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Offen
authors.affiliation: Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Viksoe-Nielsen
authors.affiliation: Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark.
authors.forename: Torben V
authors.initials: TV
authors.lastname: Borchert
authors.affiliation: York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England.
authors.forename: Keith S
authors.initials: KS
authors.lastname: Wilson
authors.affiliation: York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England.
authors.forename: Gideon J
authors.initials: GJ
authors.lastname: Davies
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D040681:Structural Homology, Protein; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D000516:alpha-Amylases; C582722:termamyl
keywords: Geobacillus stearothermophilus; Termamyl; amylase