4GUF

1.5 Angstrom Crystal Structure of the Salmonella enterica 3-Dehydroquinate Dehydratase (aroD) E86A Mutant

4GUF の概要

• エントリーDOI: 10.2210/pdb4guf/pdb
• 関連するPDBエントリー: 4GUG 4GUH 4GUI 4GUJ
• 分子名称: 3-dehydroquinate dehydratase, CHLORIDE ION (3 entities in total)
• 機能のキーワード: structural genomics, niaid, national institute of allergy and infectious diseases, center for structural genomics of infectious diseases, csgid, tim barrel, lyase
• 由来する生物種: Salmonella enterica subsp. enterica serovar Typhimurium
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 60122.00

構造登録者

Light, S.H.,Minasov, G.,Duban, M.-E.,Shuvalova, L.,Kwon, K.,Lavie, A.,Anderson, W.F.,Center for Structural Genomics of Infectious Diseases (CSGID) (登録日: 2012-08-29, 公開日: 2012-09-12, 最終更新日: 2023-09-13)

主引用文献

Light, S.H.,Anderson, W.F.,Lavie, A.
Reassessing the type I dehydroquinate dehydratase catalytic triad: Kinetic and structural studies of Glu86 mutants.
Protein Sci., 22:418-424, 2013

PubMed Abstract: Dehydroquinate dehydratase (DHQD) catalyzes the third reaction in the biosynthetic shikimate pathway. Type I DHQDs are members of the greater aldolase superfamily, a group of enzymes that contain an active site lysine that forms a Schiff base intermediate. Three residues (Glu86, His143, and Lys170 in the Salmonella enterica DHQD) have previously been proposed to form a triad vital for catalysis. While the roles of Lys170 and His143 are well defined-Lys170 forms the Schiff base with the substrate and His143 shuttles protons in multiple steps in the reaction-the role of Glu86 remains poorly characterized. To probe Glu86's role, Glu86 mutants were generated and subjected to biochemical and structural study. The studies presented here demonstrate that mutant enzymes retain catalytic proficiency, calling into question the previously attributed role of Glu86 in catalysis and suggesting that His143 and Lys170 function as a catalytic dyad. Structures of the Glu86Ala (E86A) mutant in complex with covalently bound reaction intermediate reveal a conformational change of the His143 side chain. This indicates a predominant steric role for Glu86, to maintain the His143 side chain in position consistent with catalysis. The structures also explain why the E86A mutant is optimally active at more acidic conditions than the wild-type enzyme. In addition, a complex with the reaction product reveals a novel, likely nonproductive, binding mode that suggests a mechanism of competitive product inhibition and a potential strategy for the design of therapeutics.

PubMed: 23341204
DOI: 10.1002/pro.2218

実験手法

X-RAY DIFFRACTION (1.5 Å)