1G1Y

CRYSTAL STRUCTURE OF ALPHA-AMYLASE II (TVAII) FROM THERMOACTINOMYCES VULGARIS R-47 AND BETA-CYCLODEXTRIN COMPLEX

Summary for 1G1Y

• Entry DOI: 10.2210/pdb1g1y/pdb
• Related PRD ID: PRD_900012
• Descriptor: ALPHA-AMYLASE II, Cycloheptakis-(1-4)-(alpha-D-glucopyranose) (3 entities in total)
• Functional Keywords: hydrolase
• Biological source: Thermoactinomyces vulgaris
• Total number of polymer chains: 2
• Total formula weight: 137298.16

Authors

Kondo, S.,Ohtaki, A.,Tonozuka, T.,Sakano, Y.,Kamitori, S. (deposition date: 2000-10-16, release date: 2001-03-14, Last modification date: 2024-02-07)

Primary citation

Kondo, S.,Ohtaki, A.,Tonozuka, T.,Sakano, Y.,Kamitori, S.
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.
J.Biochem.(Tokyo), 129:423-428, 2001

PubMed Abstract: 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.

PubMed: 11226882

Experimental method

X-RAY DIFFRACTION (3 Å)