1jae
From Proteopedia
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STRUCTURE OF TENEBRIO MOLITOR LARVAL ALPHA-AMYLASE
Overview
The three-dimensional structure of the alpha-amylase from Tenebrio molitor larvae (TMA) has been determined by molecular replacement techniques using diffraction data of a crystal of space group P212121 (a=51.24 A; b=93.46 A; c=96.95 A). The structure has been refined to a crystallographic R-factor of 17.7% for 58,219 independent reflections in the 7.0 to 1.64 A resolution range, with root-mean-square deviations of 0.008 A for bond lengths and 1.482 degrees for bond angles. The final model comprises all 471 residues of TMA, 261 water molecules, one calcium cation and one chloride anion. The electron density confirms that the N-terminal glutamine residue has undergone a post-transitional modification resulting in a stable 5-oxo-proline residue. The X-ray structure of TMA provides the first three-dimensional model of an insect alpha-amylase.The monomeric enzyme exhibits an elongated shape approximately 75 Ax46 Ax40 A and consists of three distinct domains, in line with models for alpha-amylases from microbial, plant and mammalian origin. However, the structure of TMA reflects in the substrate and inhibitor binding region a remarkable difference from mammalian alpha-amylases: the lack of a highly flexible, glycine-rich loop, which has been proposed to be involved in a "trap-release" mechanism of substrate hydrolysis by mammalian alpha-amylases. The structural differences between alpha-amylases of various origins might explain the specificity of inhibitors directed exclusively against insect alpha-amylases.
About this Structure
1JAE is a Single protein structure of sequence from Tenebrio molitor with and as ligands. Active as Alpha-amylase, with EC number 3.2.1.1 Full crystallographic information is available from OCA.
Reference
Crystal structure of yellow meal worm alpha-amylase at 1.64 A resolution., Strobl S, Maskos K, Betz M, Wiegand G, Huber R, Gomis-Ruth FX, Glockshuber R, J Mol Biol. 1998 May 8;278(3):617-28. PMID:9600843
Page seeded by OCA on Thu Feb 21 13:20:25 2008
