5BCA

BETA-AMYLASE FROM BACILLUS CEREUS VAR. MYCOIDES

Summary for 5BCA

• Entry DOI: 10.2210/pdb5bca/pdb
• Descriptor: PROTEIN (1,4-ALPHA-D-GLUCAN MALTOHYDROLASE.), CALCIUM ION (3 entities in total)
• Functional Keywords: hydrolase, beta-amylase, raw-starch binding domain
• Biological source: Bacillus cereus
• Total number of polymer chains: 4
• Total formula weight: 233594.40

Authors

Oyama, T.,Kusunoki, M.,Kishimoto, Y.,Takasaki, Y.,Nitta, Y. (deposition date: 1999-03-12, release date: 2000-03-15, Last modification date: 2024-11-13)

Primary citation

Oyama, T.,Kusunoki, M.,Kishimoto, Y.,Takasaki, Y.,Nitta, Y.
Crystal structure of beta-amylase from Bacillus cereus var. mycoides at 2.2 A resolution.
J.Biochem.(Tokyo), 125:1120-1130, 1999

PubMed Abstract: The crystal structure of beta-amylase from Bacillus cereus var. mycoides was determined by the multiple isomorphous replacement method. The structure was refined to a final R-factor of 0.186 for 102,807 independent reflections with F/sigma(F) > or = 2.0 at 2.2 A resolution with root-mean-square deviations from ideality in bond lengths, and bond angles of 0.014 A and 3.00 degrees, respectively. The asymmetric unit comprises four molecules exhibiting a dimer-of-dimers structure. The enzyme, however, acts as a monomer in solution. The beta-amylase molecule folds into three domains; the first one is the N-terminal catalytic domain with a (beta/alpha)8 barrel, the second one is the excursion part from the first one, and the third one is the C-terminal domain with two almost anti-parallel beta-sheets. The active site cleft, including two putative catalytic residues (Glu172 and Glu367), is located on the carboxyl side of the central beta-sheet in the (beta/alpha)8 barrel, as in most amylases. The active site structure of the enzyme resembles that of soybean beta-amylase with slight differences. One calcium ion is bound per molecule far from the active site. The C-terminal domain has a fold similar to the raw starch binding domains of cyclodextrin glycosyltransferase and glucoamylase.

PubMed: 10348915

Experimental method

X-RAY DIFFRACTION (2.2 Å)