2ZRX

Crystal structure of Sulfolobus shibatae isopentenyl diphosphate isomerase in complex with FMN and DMAPP.

2ZRX の概要

• エントリーDOI: 10.2210/pdb2zrx/pdb
• 関連するPDBエントリー: 2ZRU 2ZRV 2ZRW 2ZRY 2ZRZ
• 分子名称: Isopentenyl-diphosphate delta-isomerase, FLAVIN MONONUCLEOTIDE, DIMETHYLALLYL DIPHOSPHATE, ... (5 entities in total)
• 機能のキーワード: type 2, idi, fmn, dmapp, isopentenyl diphosphate isomerase, flavoprotein, isomerase, isoprene biosynthesis, nadp
• 由来する生物種: Sulfolobus shibatae
• 細胞内の位置: Cytoplasm (By similarity): P61615
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 164810.23

構造登録者

Unno, H.,Yamashita, S.,Ikeda, Y.,Sekiguchi, S.,Yoshida, N.,Yoshimura, T.,Kusunoki, M.,Nakayama, T.,Nishino, T.,Hemmi, H. (登録日: 2008-09-01, 公開日: 2009-01-20, 最終更新日: 2024-03-13)

主引用文献

Unno, H.,Yamashita, S.,Ikeda, Y.,Sekiguchi, S.Y.,Yoshida, N.,Yoshimura, T.,Kusunoki, M.,Nakayama, T.,Nishino, T.,Hemmi, H.
New role of flavin as a general acid-base catalyst with no redox function in type 2 isopentenyl-diphosphate isomerase.
J.Biol.Chem., 284:9160-9167, 2009

PubMed Abstract: Using FMN and a reducing agent such as NAD(P)H, type 2 isopentenyl-diphosphate isomerase catalyzes isomerization between isopentenyl diphosphate and dimethylallyl diphosphate, both of which are elemental units for the biosynthesis of highly diverse isoprenoid compounds. Although the flavin cofactor is expected to be integrally involved in catalysis, its exact role remains controversial. Here we report the crystal structures of the substrate-free and complex forms of type 2 isopentenyl-diphosphate isomerase from the thermoacidophilic archaeon Sulfolobus shibatae, not only in the oxidized state but also in the reduced state. Based on the active-site structures of the reduced FMN-substrate-enzyme ternary complexes, which are in the active state, and on the data from site-directed mutagenesis at highly conserved charged or polar amino acid residues around the active site, we demonstrate that only reduced FMN, not amino acid residues, can catalyze proton addition/elimination required for the isomerase reaction. This discovery is the first evidence for this long suspected, but previously unobserved, role of flavins just as a general acid-base catalyst without playing any redox roles, and thereby expands the known functions of these versatile coenzymes.

PubMed: 19158086
DOI: 10.1074/jbc.M808438200

実験手法

X-RAY DIFFRACTION (3 Å)