9US3
Klebsiella pneumoniae maltohexaose-producing alpha-amylase
Summary for 9US3
Entry DOI | 10.2210/pdb9us3/pdb |
Descriptor | Maltohexaose-producing amylase, CALCIUM ION (3 entities in total) |
Functional Keywords | glycosyl hydrolase family 13, hydrolase |
Biological source | Klebsiella pneumoniae |
Total number of polymer chains | 2 |
Total formula weight | 148702.17 |
Authors | |
Primary citation | Fujimoto, Z.,Kishine, N.,Momma, M. Crystal structure of Klebsiella pneumoniae maltohexaose-producing alpha-amylase. J.Biochem., 2025 Cited by PubMed Abstract: The α-amylase from Klebsiella pneumoniae (KpAmy13), which belongs to glycoside hydrolase family 13 subfamily 19, produces maltohexaose as an initial product when acting on starch and has been characterized as a maltohexaose-producing α-amylase. The crystal structure of KpAmy13 was determined at a resolution of 1.9 Å, revealing the structures of all its domains: N, A, B, and C. Domain N resembles the starch-binding domain known as carbohydrate-binding module family 69, found in α-glucan-related proteins. Although domain N does not conserve the starch-binding residues observed in other proteins, it has several hydrophobic residues on its surface, which might be involved in promoting catalysis. The catalytic cleft is located at the bottom of a circular depression. The domain N-truncated mutant of KpAmy13 in complex with maltohexaose showed that its non-reducing end glucose docks at subsite -6. The long and complex structure of domain B contributes to forming a cleft of the right size for six glucose moieties, demonstrating the exo-acting mechanism. PubMed: 40576559DOI: 10.1093/jb/mvaf034 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (1.899 Å) |
Structure validation
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