Crystal structure of recombinant soybean beta-amylase complexed with beta-cyclodextrin.Adachi, M., Mikami, B., Katsube, T., Utsumi, S.
(1998) J.Biol.Chem. 273: 19859-19865
- PubMed: 9677422
- PubMed Abstract:
- Crystal Structures of Soybean Beta-Amylase Reacted with Beta-Maltose and Maltal: Active Site Components and Their Apparent Roles in Catalysis
Mikami, B.,Degano, M.,Hehre, E.J.,Sacchettini, J.C.
(1994) Biochemistry 33: 7779
- The 2.0-A Resolution Structure of Soybean Beta-Amylase Complexed with Alpha-Cyclodextrin
Mikami, B.,Hehre, E.J.,Sato, M.,Katsube, Y.,Hirose, M.,Morita, Y.,Sacchettini, J.C.
(1993) Biochemistry 32: 6836
In order to study the interaction of soybean beta-amylase with substrate, we solved the crystal structure of beta-cyclodextrin-enzyme complex and compared it with that of alpha-cyclodextrin-enzyme complex. The enzyme was expressed in Escherichia coli ...
In order to study the interaction of soybean beta-amylase with substrate, we solved the crystal structure of beta-cyclodextrin-enzyme complex and compared it with that of alpha-cyclodextrin-enzyme complex. The enzyme was expressed in Escherichia coli at a high level as a soluble and catalytically active protein. The purified recombinant enzyme had properties nearly identical to those of native soybean beta-amylase and formed the same crystals as the native enzyme. The crystal structure of recombinant enzyme complexed with beta-cyclodextrin was refined at 2. 07-A resolution with a final crystallographic R value of 15.8% (Rfree = 21.1%). The root mean square deviation in the position of C-alpha atoms between this recombinant enzyme and the native enzyme was 0.22 A. These results indicate that the expression system established here is suitable for studying structure-function relationships of beta-amylase. The conformation of the bound beta-cyclodextrin takes an ellipsoid shape in contrast to the circular shape of the bound alpha-cyclodextrin. The cyclodextrins shared mainly two glucose binding sites, 3 and 4. The glucose residue 4 was slightly shifted from the maltose binding site. This suggests that the binding site of the cyclodextrins is important for its holding of a cleaved substrate, which enables the multiple attack mechanism of beta-amylase.
Research Institute for Food Science, Kyoto University, Uji Kyoto 611-0011, Japan.