4KXU

Human transketolase in covalent complex with donor ketose D-fructose-6-phosphate

4KXU の概要

• エントリーDOI: 10.2210/pdb4kxu/pdb
• 分子名称: Transketolase, 1,2-ETHANEDIOL, MAGNESIUM ION, ... (7 entities in total)
• 機能のキーワード: thiamin diphosphate, enzyme catalysis, pentose phosphate pathway, transferase
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 71064.97

構造登録者

Neumann, P.,Luedtke, S.,Ficner, R.,Tittmann, K. (登録日: 2013-05-28, 公開日: 2013-08-21, 最終更新日: 2023-09-20)

主引用文献

Ludtke, S.,Neumann, P.,Erixon, K.M.,Leeper, F.,Kluger, R.,Ficner, R.,Tittmann, K.
Sub-angstrom-resolution crystallography reveals physical distortions that enhance reactivity of a covalent enzymatic intermediate.
Nat Chem, 5:762-767, 2013

PubMed Abstract: It is recognized widely that enzymes promote reactions by providing a pathway that proceeds through a transition state of lower energy. In principle, further rate enhancements could be achieved if intermediates are prevented from relaxing to their lowest energy state, and thereby reduce the barrier to the subsequent transition state. Here, we report sub-ångström-resolution crystal structures of genuine covalent reaction intermediates of transketolase. These structures reveal a pronounced out-of-plane distortion of over 20° for the covalent bond that links cofactor and substrate, and a specific elongation of the scissile substrate carbon-carbon bond (d > 1.6 Å). To achieve these distortions, the protein's conformation appears to prevent relaxation of a substrate-cofactor intermediate. The results implicate a reduced barrier to the subsequent step that is consistent with an intermediate of raised energy and leads to a more efficient overall process.

PubMed: 23965678
DOI: 10.1038/nchem.1728

実験手法

X-RAY DIFFRACTION (0.98 Å)