5AXG

Crystal structure of thermophilic dextranase from Thermoanaerobacter pseudethanolicus

5AXG の概要

• エントリーDOI: 10.2210/pdb5axg/pdb
• 関連するPDBエントリー: 5AXH
• 分子名称: Dextranase, PHOSPHATE ION, 1,2-ETHANEDIOL, ... (6 entities in total)
• 機能のキーワード: glycoside hydrolase family 66, hydrolase
• 由来する生物種: Thermoanaerobacter pseudethanolicus ATCC 33223
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 144349.84

構造登録者

Suzuki, N.,Kishine, N.,Fujimoto, Z.,Sakurai, M.,Momma, M.,Ko, J.A.,Nam, S.H.,Kimura, A.,Kim, Y.M. (登録日: 2015-07-29, 公開日: 2015-11-11, 最終更新日: 2023-11-08)

主引用文献

Suzuki, N.,Kishine, N.,Fujimoto, Z.,Sakurai, M.,Momma, M.,Ko, J.A.,Nam, S.H.,Kimura, A.,Kim, Y.M.
Crystal structure of thermophilic dextranase from Thermoanaerobacter pseudethanolicus
J.Biochem., 159:331-339, 2016

PubMed Abstract: The crystal structures of the wild type and catalytic mutant Asp-312→Gly in complex with isomaltohexaose of endo-1,6-dextranase from the thermophilic bacterium Thermoanaerobacter pseudethanolicus (TpDex), belonging to the glycoside hydrolase family 66, were determined. TpDex consists of three structural domains, a catalytic domain comprising an (β/α)8-barrel and two β-domains located at both N- and C-terminal ends. The isomaltohexaose-complex structure demonstrated that the isomaltohexaose molecule was bound across the catalytic site, showing that TpDex had six subsites (-4 to +2) in the catalytic cleft. Marked movement of the Trp-376 side-chain along with loop 6, which was the side wall component of the cleft at subsite +1, was observed to occupy subsite +1, indicating that it might expel the cleaved aglycone subsite after the hydrolysis reaction. Structural comparison with other mesophilic enzymes indicated that several structural features of TpDex, loop deletion, salt bridge and surface-exposed charged residue, may contribute to thermostability.

PubMed: 26494689
DOI: 10.1093/jb/mvv104

実験手法

X-RAY DIFFRACTION (1.85 Å)