5HQX

Crystal structure of maize cytokinin oxidase/dehydrogenase 4 (ZmCKO4) in complex with phenylurea inhibitor HETDZ

5HQX の概要

• エントリーDOI: 10.2210/pdb5hqx/pdb
• 関連するPDBエントリー: 4O95 4OAL 5HMR
• 分子名称: Cytokinin dehydrogenase 4, FLAVIN-ADENINE DINUCLEOTIDE, 1-[2-(2-hydroxyethyl)phenyl]-3-(1,2,3-thiadiazol-5-yl)urea, ... (4 entities in total)
• 機能のキーワード: flavoenzyme, cytokinin degradation, oxidase/dehydrogenase, rossmann fold, oxidoreductase
• 由来する生物種: Zea mays (Maize)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 57329.12

構造登録者

Kopecny, D.,Koncitikova, R.,Briozzo, P. (登録日: 2016-01-22, 公開日: 2016-07-27, 最終更新日: 2024-11-06)

主引用文献

Nisler, J.,Kopecny, D.,Koncitikova, R.,Zatloukal, M.,Bazgier, V.,Berka, K.,Zalabak, D.,Briozzo, P.,Strnad, M.,Spichal, L.
Novel thidiazuron-derived inhibitors of cytokinin oxidase/dehydrogenase.
Plant Mol.Biol., 92:235-248, 2016

PubMed Abstract: Two new TDZ derivatives (HETDZ and 3FMTDZ) are very potent inhibitors of CKX and are promising candidates for in vivo studies. Cytokinin hormones regulate a wide range of essential processes in plants. Thidiazuron (N-phenyl-N'-1,2,3-thiadiazol-5-yl urea, TDZ), formerly registered as a cotton defoliant, is a well known inhibitor of cytokinin oxidase/dehydrogenase (CKX), an enzyme catalyzing the degradation of cytokinins. TDZ thus increases the lifetime of cytokinins and their effects in plants. We used in silico modeling to design, synthesize and characterize twenty new TDZ derivatives with improved inhibitory properties. Two compounds, namely 1-[1,2,3]thiadiazol-5-yl-3-(3-trifluoromethoxy-phenyl)urea (3FMTDZ) and 1-[2-(2-hydroxyethyl)phenyl]-3-(1,2,3-thiadiazol-5-yl)urea (HETDZ), displayed up to 15-fold lower IC 50 values compared with TDZ for AtCKX2 from Arabidopsis thaliana and ZmCKX1 and ZmCKX4a from Zea mays. Binding modes of 3FMTDZ and HETDZ were analyzed by X-ray crystallography. Crystal structure complexes, solved at 2.0 Å resolution, revealed that HETDZ and 3FMTDZ bound differently in the active site of ZmCKX4a: the thiadiazolyl ring of 3FMTDZ was positioned over the isoalloxazine ring of FAD, whereas that of HETDZ had the opposite orientation, pointing toward the entrance of the active site. The compounds were further tested for cytokinin activity in several cytokinin bioassays. We suggest that the combination of simple synthesis, lowered cytokinin activity, and enhanced inhibitory effects on CKX isoforms, makes 3FMTDZ and HETDZ suitable candidates for in vivo studies.

PubMed: 27422623
DOI: 10.1007/s11103-016-0509-0

実験手法

X-RAY DIFFRACTION (2.05 Å)