1j0y
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beta-amylase from Bacillus cereus var. mycoides in complex with glucose
OverviewOverview
The crystal structures of beta-amylase from Bacillus cereus var. mycoides, in complexes with five inhibitors were solved. The inhibitors used were, three substrate analogs, i.e. glucose, maltose (product), and a, synthesized compound, O-alpha-D-glucopyranosyl-(1-->4)-O-alpha-D-glucopyranosyl-(1-->4)-D-xylopy, ranose (GGX), and two affinity-labeling reagents with an epoxy alkyl group, at the reducing end of glucose. For all inhibitors, one molecule was bound, at the active site cleft and the non-reducing end glucose of the four, inhibitors except GGX was located at subsite 1, accompanied by a large, conformational change of the flexible loop (residues 93-97), which covered, the bound inhibitor. In addition, another molecule of maltose or GGX was, bound about 30 A away from the active site. A large movement of residues, 330 and 331 around subsite 3 was also observed upon the binding of GGX at, subsites 3 to 5. Two affinity-labeling reagents, alpha-EPG and alpha-EBG, were covalently bound to a catalytic residue (Glu-172). A substrate, recognition mechanism for the beta-amylase was discussed based on the, modes of binding of these inhibitors in the active site cleft.
About this StructureAbout this Structure
1J0Y is a Single protein structure of sequence from Bacillus cereus with GLC and CA as ligands. Active as Beta-amylase, with EC number 3.2.1.2 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of beta-amylase from Bacillus cereus var mycoides in complexes with substrate analogs and affinity-labeling reagents., Oyama T, Miyake H, Kusunoki M, Nitta Y, J Biochem (Tokyo). 2003 Apr;133(4):467-74. PMID:12761294
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