1J0J

Crystal structure of neopullulanase E357Q complex with maltotetraose

1J0J の概要

• エントリーDOI: 10.2210/pdb1j0j/pdb
• 関連するPDBエントリー: 1J0H 1J0I 1J0K
• 関連するBIRD辞書のPRD_ID: PRD_900010
• 分子名称: neopullulanase, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• 機能のキーワード: beta-alpha-barrels, hydrolase
• 由来する生物種: Geobacillus stearothermophilus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 139616.87

構造登録者

Hondoh, H.,Kuriki, T.,Matsuura, Y. (登録日: 2002-11-14, 公開日: 2003-01-28, 最終更新日: 2023-12-27)

主引用文献

Hondoh, H.,Kuriki, T.,Matsuura, Y.
Three-dimensional structure and substrate binding of Bacillus stearothermophilus neopullulanase
J.Mol.Biol., 326:177-188, 2003

PubMed Abstract: Crystal structures of Bacillus stearothermophilus TRS40 neopullulanase and its complexes with panose, maltotetraose and isopanose were determined at resolutions of 1.9, 2.4, 2.8 and 3.2A, respectively. Since the latter two carbohydrates are substrates of this enzyme, a deactivated mutant at the catalytic residue Glu357-->Gln was used for complex crystallization. The structures were refined at accuracies with r.m.s. deviations of bond lengths and bond angles ranging from 0.005A to 0.008A and 1.3 degrees to 1.4 degrees, respectively. The active enzyme forms a dimer in the crystalline state and in solution. The monomer enzyme is composed of four domains, N, A, B and C, and has a (beta/alpha)(8)-barrel in domain A. The active site lies between domain A and domain N from the other monomer. The results show that dimer formation makes the active-site cleft narrower than those of ordinary alpha-amylases, which may contribute to the unique substrate specificity of this enzyme toward both alpha-1,4 and alpha-1,6-glucosidic linkages. This specificity may be influenced by the subsite structure. Only subsites -1 and -2 are commonly occupied by the product and substrates, suggesting that equivocal recognition occurs at the other subsites, which contributes to the wide substrate specificity of this enzyme.

PubMed: 12547200
DOI: 10.1016/S0022-2836(02)01402-X

実験手法

X-RAY DIFFRACTION (2.8 Å)