5FWG

TETRA-(5-FLUOROTRYPTOPHANYL)-GLUTATHIONE TRANSFERASE

5FWG の概要

• エントリーDOI: 10.2210/pdb5fwg/pdb
• 分子名称: TETRA-(5-FLUOROTRYPTOPHANYL)-GLUTATHIONE TRANSFERASE MU CLASS, (9R,10R)-9-(S-GLUTATHIONYL)-10-HYDROXY-9,10-DIHYDROPHENANTHRENE (3 entities in total)
• 機能のキーワード: glutathione transferase, unnatural amino acid, 5-fluorotryptophan, three-dimensional structure, transferase
• 由来する生物種: Rattus norvegicus (Norway rat)
• 細胞内の位置: Cytoplasm: P04905
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 52784.62

構造登録者

Parsons, J.F.,Xiao, G.,Armstrong, R.N.,Gilliland, G.L. (登録日: 1997-11-08, 公開日: 1999-01-27, 最終更新日: 2023-08-09)

主引用文献

Parsons, J.F.,Xiao, G.,Gilliland, G.L.,Armstrong, R.N.
Enzymes harboring unnatural amino acids: mechanistic and structural analysis of the enhanced catalytic activity of a glutathione transferase containing 5-fluorotryptophan.
Biochemistry, 37:6286-6294, 1998

PubMed Abstract: The catalytic characteristics and structure of the M1-1 isoenzyme of rat glutathione (GSH) transferase in which all four tryptophan residues in each monomer are replaced with 5-fluorotryptophan are described. The fluorine-for-hydrogen substitution does not change the interaction of the enzyme with GSH even though two tryptophan residues (Trp7 and Trp45) are involved in direct hydrogen-bonding interactions with the substrate. The rate constants for association and dissociation of the peptide, measured by stopped-flow spectrometry, remain unchanged by the unnatural amino acid. The 5-FTrp-substituted enzyme exhibits a kcat of 73 s-1 as compared to 18 s-1 for the native enzyme toward 1-chloro-2,4-dinitrobenzene. That the increase in the turnover number is due to an enhanced rate of product release in the mutant is confirmed by the kinetics of the approach to equilibrium for binding of the product. The crystal structure of the 5-FTrp-containing enzyme was solved at a resolution of 2.0 A by difference Fourier techniques. The structure reveals local conformational changes in the structural elements that define the approach to the active site which are attributed to steric interactions of the fluorine atoms associated with 5-FTrp146 and 5-FTrp214 in domain II. These changes appear to result in the enhanced rate of product release. This structure represents the first of a protein substituted with 5-fluorotryptophan.

PubMed: 9572843
DOI: 10.1021/bi980219e

実験手法

X-RAY DIFFRACTION (2 Å)