5YX3

Chalcone isomerase from the Antarctic vascular plant Deschampsia Antarctica (DaCHI1)

5YX3 の概要

• エントリーDOI: 10.2210/pdb5yx3/pdb
• 分子名称: Chalcone-flavonone isomerase family protein (2 entities in total)
• 機能のキーワード: chalcone isomerase, deschampsia antarctica, isomerase
• 由来する生物種: Deschampsia antarctica (Antarctic hair grass)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 47918.14

構造登録者

Lee, C.W.,Park, S.,Lee, J.H. (登録日: 2017-12-01, 公開日: 2018-02-21, 最終更新日: 2024-03-27)

主引用文献

Park, S.H.,Lee, C.W.,Cho, S.M.,Lee, H.,Park, H.,Lee, J.,Lee, J.H.
Crystal structure and enzymatic properties of chalcone isomerase from the Antarctic vascular plant Deschampsia antarctica Desv.
PLoS ONE, 13:e0192415-e0192415, 2018

PubMed Abstract: Chalcone isomerase (CHI) is an important enzyme for flavonoid biosynthesis that catalyzes the intramolecular cyclization of chalcones into (S)-flavanones. CHIs have been classified into two types based on their substrate specificity. Type I CHIs use naringenin chalcone as a substrate and are found in most of plants besides legumes, whereas type II CHIs in leguminous plants can also utilize isoliquiritigenin. In this study, we found that the CHI from the Antarctic plant Deschampsia antarctica (DaCHI1) is of type I based on sequence homology but can use type II CHI substrates. To clarify the enzymatic mechanism of DaCHI1 at the molecular level, the crystal structures of unliganded DaCHI1 and isoliquiritigenin-bound DaCHI1 were determined at 2.7 and 2.1 Å resolutions, respectively. The structures revealed that isoliquiritigenin binds to the active site of DaCHI1 and induces conformational changes. Additionally, the activity assay showed that while DaCHI1 exhibits substrate preference for naringenin chalcone, it can also utilize isoliquiritigenin although the catalytic activity was relatively low. Based on these results, we propose that DaCHI1 uses various substrates to produce antioxidant flavonoids as an adaptation to oxidative stresses associated with harsh environmental conditions.

PubMed: 29394293
DOI: 10.1371/journal.pone.0192415

実験手法

X-RAY DIFFRACTION (2.7 Å)