1MI4

Glyphosate insensitive G96A mutant EPSP synthase liganded with shikimate-3-phosphate

1MI4 の概要

• エントリーDOI: 10.2210/pdb1mi4/pdb
• 関連するPDBエントリー: 1G6S 1G6T
• 分子名称: 5-enolpyruvylshikimate-3-phosphate synthase, SHIKIMATE-3-PHOSPHATE, FORMIC ACID, ... (4 entities in total)
• 機能のキーワード: inside-out alpha-beta barrel, transferase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm : P0A6D3
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 47054.12

構造登録者

Eschenburg, S.,Healy, M.L.,Priestman, M.A.,Lushington, G.H.,Schonbrunn, E. (登録日: 2002-08-21, 公開日: 2002-12-18, 最終更新日: 2023-10-25)

主引用文献

Eschenburg, S.,Healy, M.L.,Priestman, M.A.,Lushington, G.H.,Schonbrunn, E.
How the mutation glycine96 to alanine confers glyphosate insensitivity to 5-enolpyruvyl shikimate-3-phosphate synthase from Escherichia coli.
PLANTA, 216:129-135, 2002

PubMed Abstract: The enzyme 5-enolpyruvyl shikimate-3-phosphate (EPSP) synthase (EC 2.5.1.19) is essential for the biosynthesis of aromatic compounds in plants and microbes and is the unique target of the herbicide glyphosate. One of the first glyphosate-insensitive enzymes reported was a Gly96Ala mutant of EPSP synthase from Klebsiella pneumoniae. We have introduced this single-site mutation into the highly homologous EPSP synthase from Escherichia coli. The mutant enzyme is insensitive to glyphosate with unaltered affinity for its first substrate, shikimate-3-phosphate (S3P), but displays a 30-fold lower affinity for its second substrate, phosphoenolpyruvate (PEP). Using X-ray crystallography, we solved the structure of Gly96Ala-EPSP synthase liganded with S3P to 0.17 nm resolution. The crystal structure shows that the additional methyl group from Ala96 protrudes into the active site of the enzyme. While the interactions between enzyme and S3P remain unaffected, the accessible volume for glyphosate binding is substantially reduced. Exploiting the crystallographic results for molecular modeling, we demonstrate that PEP but not glyphosate can be docked in the Gly96Ala-modified binding site. The predicted PEP binding site satisfies the earlier proposed interaction pattern for PEP with EPSP synthase and corroborates the assumption that glyphosate and PEP target the same binding site.

PubMed: 12430021
DOI: 10.1007/s00425-002-0908-0

実験手法

X-RAY DIFFRACTION (1.7 Å)