Three-dimensional structure of soybean beta-amylase determined at 3.0 A resolution: preliminary chain tracing of the complex with alpha-cyclodextrin.
The three-dimensional structure of a complex of soybean beta-amylase [EC 3.2.1.2] with an inhibitor, alpha-cyclodextrin, has been determined at 3.0 A resolution by X-ray diffraction analysis. Preliminary chain tracing showed that the enzyme folded into large and small domains. The large domain has a (beta alpha)8 super-secondary structure, while the smaller one is formed from two long loops extending from the beta 3 and beta 4 strands of the (beta alpha)8 structure. The interface of the two domains together with shorter loops from the (beta alpha)8 structure form a deep cleft, in which alpha-cyclodextrin binds slightly away from the center. Two maltose molecules also bind in the cleft. One shares a binding site with alpha-cyclodextrin and the other is situated more deeply in the cleft.
Mikami
B
B
Research Institute for Food Science, Kyoto University.
Sato
M
M
Shibata
T
T
Hirose
M
M
Aibara
S
S
Katsube
Y
Y
Morita
Y
Y
D001665:Binding Sites; D003505:Cyclodextrins / Q000737:chemistry* / Q000494:pharmacology; D046911:Macromolecular Substances; D015394:Molecular Structure; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013025:Glycine max / Q000201:enzymology*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014961:X-Ray Diffraction; D047391:alpha-Cyclodextrins; D001614:beta-Amylase / Q000037:antagonists & inhibitors / Q000737:chemistry*
D003505:Cyclodextrins; D046911:Macromolecular Substances; D010940:Plant Proteins; D013438:Sulfhydryl Compounds; D047391:alpha-Cyclodextrins; D001614:beta-Amylase; C032613:alpha-cyclodextrin