1S3U

Structure Determination of Tetrahydroquinazoline Antifolates in Complex with Human and Pneumocystis carinii Dihydrofolate Reductase: Correlations of Enzyme Selectivity and Stereochemistry

1S3U の概要

• エントリーDOI: 10.2210/pdb1s3u/pdb
• 分子名称: Dihydrofolate reductase, SULFATE ION, (2R,6S)-6-{[methyl(3,4,5-trimethoxyphenyl)amino]methyl}-1,2,5,6,7,8-hexahydroquinazoline-2,4-diamine, ... (4 entities in total)
• 機能のキーワード: dihydrofolate reductase, inhibitor complex, oxidoreductase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Mitochondrion : P00374
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 21917.12

構造登録者

Cody, V.,Luft, J.R.,Pangborn, W.,Gangjee, A.,Queener, S.F. (登録日: 2004-01-14, 公開日: 2004-03-30, 最終更新日: 2024-02-14)

主引用文献

Cody, V.,Luft, J.R.,Pangborn, W.,Gangjee, A.,Queener, S.F.
Structure determination of tetrahydroquinazoline antifolates in complex with human and Pneumocystis carinii dihydrofolate reductase: correlations between enzyme selectivity and stereochemistry.
Acta Crystallogr.,Sect.D, 60:646-655, 2004

PubMed Abstract: Structural data are reported for the first examples of the tetrahydroquinazoline antifolate (6R,6S)-2,4-diamino-6-(1-indolinomethyl)-5,6,7,8-tetrahydroquinazoline (1) and its trimethoxy analogue (6R,6S)-2,4-diamino-6-(3',4',5'-trimethoxybenzyl)-5,6,7,8-tetrahydroquinazoline (2) as inhibitor complexes with dihydrofolate reductase (DHFR) from human (hDHFR) and Pneumocystis carinii (pcDHFR) sources. The indoline analogue (1) was crystallized as ternary complexes with NADPH and hDHFR (1.9 A resolution) and pcDHFR (2.3 A resolution), while the trimethoxy quinazoline analogue (2) was crystallized as a binary complex with hDHFR in two polymorphic rhombohedral R3 lattices: R3(1) to 1.8 A resolution and R3(2) to 2.0 A resolution. Structural analysis of these potent and selective DHFR-inhibitor complexes revealed preferential binding of the 6S-equatorial isomer in each structure. This configuration is similar to that of the natural tetrahydrofolate substrate; that is, 6S. These data also show that in both the hDHFR and pcDHFR ternary complexes with (1) the indoline ring is partially disordered, with two static conformations that differ between structures. These conformers also differ from that observed for the trimethoxybenzyl ring of tetrahydroquinazoline (2). There is also a correlation between the disorder of the flexible loop 23 and the disorder of the cofactor nicotinamide ribose ring in the pcDHFR-NADPH-(1) ternary complex. Comparison of the Toxoplasma gondii DHFR (tgDHFR) sequence with those of other DHFRs provides insight into the role of sequence and conformation in inhibitor-binding preferences which may aid in the design of novel antifolates with specific DHFR selectivity.

PubMed: 15039552
DOI: 10.1107/S0907444904002094

実験手法

X-RAY DIFFRACTION (2.5 Å)