2DFV

Hyperthermophilic threonine dehydrogenase from Pyrococcus horikoshii

2DFV の概要

• エントリーDOI: 10.2210/pdb2dfv/pdb
• 分子名称: Probable L-threonine 3-dehydrogenase, ZINC ION, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: threonine dehydrogenase, pyrococcus horikoshii, archaea, alchol dehydrogenase, ph0655, oxidoreductase
• 由来する生物種: Pyrococcus horikoshii
• 細胞内の位置: Cytoplasm (By similarity): O58389
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 116401.89

構造登録者

Ishikawa, K.,Higashi, N.,Nakamura, T.,Matsuura, T.,Nakagawa, A. (登録日: 2006-03-03, 公開日: 2007-01-16, 最終更新日: 2024-11-20)

主引用文献

Ishikawa, K.,Higashi, N.,Nakamura, T.,Matsuura, T.,Nakagawa, A.
The first crystal structure of L-threonine dehydrogenase.
J.Mol.Biol., 366:857-867, 2007

PubMed Abstract: L-threonine dehydrogenase (TDH) is an enzyme that catalyzes the oxidation of L-threonine to 2-amino-3-ketobutyrate. We solved the first crystal structure of a medium chain L-threonine dehydrogenase from a hyperthermophilic archaeon, Pyrococcus horikoshii (PhTDH), by the single wavelength anomalous diffraction method using a selenomethionine-substituted enzyme. This recombinant PhTDH is a homo-tetramer in solution. Three monomers of PhTDHs were located in the crystallographic asymmetric unit, however, the crystal structure exhibits a homo-tetramer structure with crystallographic and non-crystallographic 222 symmetry in the cell. Despite the low level of sequence identity to a medium-chain NAD(H)-dependent alcohol dehydrogenase (ADH) and the different substrate specificity, the overall folds of the PhTDH monomer and tetramer are similar to those of the other ADH. Each subunit is composed of two domains: a nicotinamide cofactor (NAD(H))-binding domain and a catalytic domain. The NAD(H)-binding domain contains the alpha/beta Rossmann fold motif, characteristic of the NAD(H)-binding protein. One molecule of PhTDH contains one zinc ion playing a structural role. This metal ion exhibits coordination with four cysteine ligands and some of the ligands are conserved throughout the structural zinc-containing ADHs and TDHs. However, the catalytic zinc ion that is coordinated at the bottom of the cleft in the case of ADH was not observed in the crystal of PhTDH. There is a significant difference in the orientation of the catalytic domain relative to the coenzyme-binding domain that results in a larger interdomain cleft.

PubMed: 17188300
DOI: 10.1016/j.jmb.2006.11.060

実験手法

X-RAY DIFFRACTION (2.05 Å)