1g1y
From Proteopedia
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CRYSTAL STRUCTURE OF ALPHA-AMYLASE II (TVAII) FROM THERMOACTINOMYCES VULGARIS R-47 AND BETA-CYCLODEXTRIN COMPLEX
Overview
Crystals of the mutant E354A of Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) complexed with beta-cyclodextrin were prepared by a soaking method, and the diffraction data were collected at 100 K, using Synchrotron radiation (SPring-8). The crystals belong to an orthorhombic system with the space group P2(1)2(1)2(1) and cell dimensions a = 111.1 A, b = 117.7 A, c = 113.3 A, which is almost isomorphous with crystals of the wild-type TVAII, and the structure was refined to an R-factor = 0.208 (R(free) = 0.252) using 3.0 A resolution data. The refined structure shows that the interactions between Phe286 and two C6 atoms of beta-cyclodextrin at the hydrolyzing site are important for TVAII to recognize cyclodextrins as substrates. This observation from the X-ray structure was supported by kinetic analyses of cyclodextrins using the wild-type TVAII, the mutant F286A and F286L. These studies also suggested that the TVAII-hydrolyzing mechanism for cyclodextrins is slightly different from that for starch.
About this Structure
1G1Y is a Single protein structure of sequence from Thermoactinomyces vulgaris with as ligand. Active as Neopullulanase, with EC number 3.2.1.135 Full crystallographic information is available from OCA.
Reference
Studies on the hydrolyzing mechanism for cyclodextrins of Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII). X-ray structure of the mutant E354A complexed with beta-cyclodextrin, and kinetic analyses on cyclodextrins., Kondo S, Ohtaki A, Tonozuka T, Sakano Y, Kamitori S, J Biochem. 2001 Mar;129(3):423-8. PMID:11226882
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