8REP

Crystal structure of oxidized ThyX-Y91F mutant

8REP の概要

• エントリーDOI: 10.2210/pdb8rep/pdb
• 分子名称: Flavin-dependent thymidylate synthase, TETRAETHYLENE GLYCOL, TRIETHYLENE GLYCOL, ... (6 entities in total)
• 機能のキーワード: flavin-dependen thymidylate synthase, methylenetetrahydrofolate, transferase
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 114594.65

構造登録者

Pecqueur, L.,Hamdane, D. (登録日: 2023-12-12, 公開日: 2025-01-01, 最終更新日: 2025-04-09)

主引用文献

Pecqueur, L.,Lombard, M.,Hamdane, D.
Structural Plasticity of Flavin-Dependent Thymidylate Synthase Controlled by the Enzyme Redox State.
Biomolecules, 15:-, 2025

PubMed Abstract: 2'-Deoxythymidine-5'-monophosphate, dTMP, is an essential precursor of thymine, one of the four canonical bases of DNA. In almost all living organisms, dTMP is synthesized de novo by a reductive methylation reaction of 2'-deoxyuridine-5'-monophosphate (dUMP) catalyzed by the thymidylate synthase, where the carbon used for the methylation is derived from methylenetetrahydrofolate (CH2THF). Many microbes, including human pathogens, utilize the flavin-dependent thymidylate synthase encoded by the gene to generate dTMP. The mechanism of action relies on the reduced coenzyme FADH, which acts both as a mediator, facilitating methylene transfer from CH2THF to dUMP, and as a reducing agent. Here, we present for the first-time crystallographic structures of ThyX from in the reduced state alone and in complex with dUMP. ThyX flavin reduction appears to order the active site, favoring a flavin conformation that drastically deviates from that observed in the oxidized enzyme. The structures show that FADH potentially controls access to the folate site and the conformation of two active site loops, affecting the degree of accessibility of substrate pockets to the solvent. Our results provide the molecular basis for the sequential enzyme mechanism implemented by ThyX during dTMP biosynthesis.

PubMed: 40149854
DOI: 10.3390/biom15030318

実験手法

X-RAY DIFFRACTION (2.201 Å)