5HJE

Crystal Structure of Transketolase complex with sedoheptulose-7-phoaphate from Pichia Stipitis

5HJE の概要

• エントリーDOI: 10.2210/pdb5hje/pdb
• 関連するPDBエントリー: 5HGX
• 分子名称: Transketolase, THIAMINE DIPHOSPHATE, CALCIUM ION, ... (5 entities in total)
• 機能のキーワード: transketolase, transferase
• 由来する生物種: Scheffersomyces stipitis CBS 6054 (Yeast)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 75810.01

構造登録者

Li, T.L.,Hsu, L.J.,Hsu, N.S. (登録日: 2016-01-13, 公開日: 2017-01-25, 最終更新日: 2023-11-08)

主引用文献

Hsu, L.J.,Hsu, N.S.,Wang, Y.L.,Wu, C.J.,Li, T.L.
Structural and biochemical interrogation on transketolase from Pichia stipitis for new functionality
Protein Eng. Des. Sel., 2016

PubMed Abstract: In the development of new functionalities of transketolase for the industrial strain Pichia stipitis (TKps) the structural information of TKps would allow us to gain insight into the enzyme's reaction mechanisms, substrates selectivity and reaction directionality to help reach the goal. We here report seven TKps crystal structures of wild type (WT) and mutants in complex with various physiological ligands. These complexes were refined to resolutions at 1.6-1.03 Å. Both biochemical and mutagenic analyses concluded that residues His27, His66, His100, His261, His478, Asp473, Arg356 and Arg525 play important roles in coenzyme binding and substrates recognition. In general, His66 and His261 hold thiamine diphosphate in place; Arg356 and Arg525 serve as gatekeepers interacting with the terminal phosphate group of sugar-phosphates. His27, His66, His100, His478 and Asp473 are critical for sugars recognition/binding, in which His27 is relatively more important in interaction with sedoheptulose-7-phosphate (S7P) than xylulose-5-phosphate (X5P) in terms of molecular recognition/binding affinity. Kinetically, the reactions with X5P (forward) which were catalyzed by WT or H27A are indistinguishable, while in the reactions with S7P (backward) H27A exhibits weaker activity relative to WT. As a result, given TKps(H27A) as the biocatalyst the overall reactivity reverses from the backward reaction preference to forward, thus facilitating net xylose assimilation.

PubMed: 27578891
DOI: 10.1093/protein/gzw036

実験手法

X-RAY DIFFRACTION (1.4 Å)