1DBR

HYPOXANTHINE GUANINE XANTHINE

1DBR の概要

• エントリーDOI: 10.2210/pdb1dbr/pdb
• 分子名称: HYPOXANTHINE GUANINE XANTHINE PHOSPHORIBOSYLTRANSFERASE, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: transferase, glycosyltransferase, purine salvage
• 由来する生物種: Toxoplasma gondii
• 細胞内の位置: Cytoplasm: Q26997
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 106186.64

構造登録者

Schumacher, M.A.,Carter, D.,Roos, D.,Ullman, B.,Brennan, R.G. (登録日: 1996-02-13, 公開日: 1997-12-03, 最終更新日: 2024-02-07)

主引用文献

Schumacher, M.A.,Carter, D.,Ross, D.S.,Ullman, B.,Brennan, R.G.
Crystal structures of Toxoplasma gondii HGXPRTase reveal the catalytic role of a long flexible loop.
Nat.Struct.Biol., 3:881-887, 1996

PubMed Abstract: Crystal structures of substrate-free and XMP-soaked hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) of the opportunistic pathogen Toxoplasma gondii have been determined to 2.4 and 2.9 A resolution, respectively. HGXPRTase displays the conserved PRTase fold. In the structure of the enzyme bound to its product, a long flexible loop (residues 115-126) is located away from the active site. Comparison to the substrate-free structure reveals a striking relocation of the loop, which is poised to cover the catalytic pocket, thus providing a mechanism by which the HG(X)PRTases shield their oxocarbonium transition states from nucleophilic attack by the bulk solvent. The conserved Ser 117-Tyr 118 dipeptide within the loop is brought to the active site, completing the ensemble of catalytic residues.

PubMed: 8836106
DOI: 10.1038/nsb1096-881

実験手法

X-RAY DIFFRACTION (2.4 Å)