1TYS

WATER-MEDIATED SUBSTRATE(SLASH)PRODUCT DISCRIMINATION: THE PRODUCT COMPLEX OF THYMIDYLATE SYNTHASE AT 1.83 ANGSTROMS

1TYS の概要

• エントリーDOI: 10.2210/pdb1tys/pdb
• 分子名称: THYMIDYLATE SYNTHASE, THYMIDINE-5'-PHOSPHATE, DIHYDROFOLIC ACID, ... (4 entities in total)
• 機能のキーワード: transferase, methyltransferase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm: P00470
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 31309.22

構造登録者

Fauman, E.,Rutenber, E.,Stroud, R. (登録日: 1993-05-07, 公開日: 1994-06-22, 最終更新日: 2024-11-20)

主引用文献

Fauman, E.B.,Rutenber, E.E.,Maley, G.F.,Maley, F.,Stroud, R.M.
Water-mediated substrate/product discrimination: the product complex of thymidylate synthase at 1.83 A.
Biochemistry, 33:1502-1511, 1994

PubMed Abstract: In an irreversible enzyme-catalyzed reaction, strong binding of the products would lead to substantial product inhibition. The X-ray crystal structure of the product complex of thymidylate synthase (1.83-A resolution, R factor = 0.183 for all data between 7.0 and 1.83 A) identifies a bound water molecule that serves to disfavor binding of the product nucleotide, dTMP. This water molecule is hydrogen bonded to absolutely conserved Tyr 146 (using the Lactobacillus casei numbering system) and is displaced by the C7 methyl group of the reaction product thymidylate. The relation between this observation and kinetic and thermodynamic values is discussed. The structure reveals a carbamate modified N-terminus that binds in a highly conserved site, replaced by side chains that can exploit the same site in other TS sequences. The enzyme-products complex is compared to the previously determined structure of enzyme-substrate-cofactor analog. This comparison reveals changes that occur between the first covalent complex formed between enzyme and substrate with an inhibitory cofactor analog and the completed reaction. The almost identical arrangement of ligands in these two structures contributes to our model for the TS reaction and verifies the physiological relevance of the mode in which potent inhibitors bind to this target for rational drug design.

PubMed: 8312270
DOI: 10.1021/bi00172a029

実験手法

X-RAY DIFFRACTION (1.8 Å)