1b90
BACILLUS CEREUS BETA-AMYLASE APO FORMBACILLUS CEREUS BETA-AMYLASE APO FORM
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystals of beta-amylase from Bacillus cereus belong to space group P21 with the following cell dimensions: a = 57.70 A, b = 92.87 A, c = 65.93 A, and beta =101.95 degrees. The structures of free and maltose-bound beta-amylases were determined by X-ray crystallography at 2.1 and 2.5 A with R-factors of 0.170 and 0.164, respectively. The final model of the maltose-bound form comprises 516 amino acid residues, four maltose molecules, 275 water molecules, one Ca2+, one acetate, and one sulfate ion. The enzyme consists of a core (beta/alpha)8-barrel domain (residues 5-434) and a C-terminal starch-binding domain (residues 435-613). Besides the active site in the core where two maltose molecules are bound in tandem, two novel maltose-binding sites were found in the core L4 region and in the C-terminal domain. The structure of the core domain is similar to that of soybean beta-amylase except for the L4 maltose-binding site, whereas the C-terminal domain has the same secondary structure as domain E of cyclodextrin glucosyltransferase. These two maltose-binding sites are 32-36 A apart from the active site. These results indicate that the ability of B. cereus beta-amylase to digest raw starch can be attributed to the additional two maltose-binding sites. Structure of raw starch-digesting Bacillus cereus beta-amylase complexed with maltose.,Mikami B, Adachi M, Kage T, Sarikaya E, Nanmori T, Shinke R, Utsumi S Biochemistry. 1999 Jun 1;38(22):7050-61. PMID:10353816[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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