3L0H

Crystal Structure Analysis of W21A mutant of human GSTA1-1 in complex with S-hexylglutathione

3L0H の概要

• エントリーDOI: 10.2210/pdb3l0h/pdb
• 関連するPDBエントリー: 3KTL
• 分子名称: Glutathione S-transferase A1, S-HEXYLGLUTATHIONE (3 entities in total)
• 機能のキーワード: thioredoxin, s-hexylglutathione, glutathione s-transferase, transferase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Cytoplasm: P08263
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 51894.96

構造登録者

Fanucchi, S.,Achilonu, I.A.,Adamson, R.J.,Fernandes, M.A.,Burke, J.P.,Dirr, H.W. (登録日: 2009-12-10, 公開日: 2010-01-12, 最終更新日: 2024-02-21)

主引用文献

Balchin, D.,Fanucchi, S.,Achilonu, I.,Adamson, R.J.,Burke, J.,Fernandes, M.,Gildenhuys, S.,Dirr, H.W.
Stability of the domain interface contributes towards the catalytic function at the H-site of class alpha glutathione transferase A1-1.
Biochim.Biophys.Acta, 1804:2228-2233, 2010

PubMed Abstract: Cytosolic glutathione transferases (GSTs) are major detoxification enzymes in aerobes. Each subunit has two distinct domains and an active site consisting of a G-site for binding GSH and an H-site for an electrophilic substrate. While the active site is located at the domain interface, the role of the stability of this interface in the catalytic function of GSTs is poorly understood. Domain 1 of class alpha GSTs has a conserved tryptophan (Trp21) in helix 1 that forms a major interdomain contact with helices 6 and 8 in domain 2. Replacing Trp21 with an alanine is structurally non-disruptive but creates a cavity between helices 1, 6 and 8 thus reducing the packing density and van der Waals contacts at the domain interface. This results in destabilization of the protein and a marked reduction in catalytic activity. While functionality at the G-site is not adversely affected by the W21A mutation, the H-site becomes more accessible to solvent and less favorable for the electrophilic substrate 1-chloro-2,4-dinitrobenzene (CDNB). Not only does the mutation result in a reduction in the energy for stabilizing the transition state formed in the S(N)Ar reaction between the substrates GSH and CDNB, it also compromises the ability of the enzyme to form and stabilize a transition state analogue (Meisenheimer complex) formed between GSH and 1,3,5-trinitrobenzene (TNB). The study demonstrates that the stability of the domain-domain interface plays a role in mediating the catalytic functionality of the active site, particularly the H-site, of class alpha GSTs.

PubMed: 20833278
DOI: 10.1016/j.bbapap.2010.09.003

実験手法

X-RAY DIFFRACTION (2.13 Å)