2GUY

Orthorhombic crystal structure (space group P21212) of Aspergillus niger alpha-amylase at 1.6 A resolution

Summary for 2GUY

• Entry DOI: 10.2210/pdb2guy/pdb
• Related: 2TAA 6TAA 7TAA
• Descriptor: Alpha-amylase A, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: (beta-alpha) 8 barrel, hydrolase
• Biological source: Aspergillus oryzae
• Cellular location: Secreted : P0C1B3
• Total number of polymer chains: 1
• Total formula weight: 53152.59

Authors

Vujicic Zagar, A. (deposition date: 2006-05-02, release date: 2006-08-15, Last modification date: 2024-11-06)

Primary citation

Vujicic-Zagar, A.,Dijkstra, B.W.
Monoclinic crystal form of Aspergillus niger alpha-amylase in complex with maltose at 1.8 angstroms resolution.
Acta Crystallogr.,Sect.F, 62:716-721, 2006

PubMed Abstract: Aspergillus niger alpha-amylase catalyses the hydrolysis of alpha-1,4-glucosidic bonds in starch. It shows 100% sequence identity to the A. oryzae homologue (also called TAKA-amylase), three crystal structures of which have been published to date. Two of them belong to the orthorhombic space group P2(1)2(1)2(1) with one molecule per asymmetric unit and one belongs to the monoclinic space group P2(1) with three molecules per asymmetric unit. Here, the purification, crystallization and structure determination of A. niger alpha-amylase crystallized in the monoclinic space group P2(1) with two molecules per asymmetric unit in complex with maltose at 1.8 angstroms resolution is reported. Furthermore, a novel 1.6 angstroms resolution orthorhombic crystal form (space group P2(1)2(1)2) of the native enzyme is presented. Four maltose molecules are observed in the maltose-alpha-amylase complex. Three of these occupy active-site subsites -2 and -1, +1 and +2 and the hitherto unobserved subsites +4 (Asp233, Gly234) and +5 (Asp235). The fourth maltose molecule binds at the distant binding sites d1 (Tyr382) and d2 (Trp385), also previously unobserved. Furthermore, it is shown that the active-site groove permits different binding modes of sugar units at subsites +1 and +2. This flexibility of the active-site cleft close to the catalytic centre might be needed for a productive binding of substrate chains and/or release of products.

PubMed: 16880540
DOI: 10.1107/S1744309106024729

Experimental method

X-RAY DIFFRACTION (1.59 Å)