6NIC

Crystal Structure of Medicago truncatula Agmatine Iminohydrolase (Deiminase) in Complex with 6-aminohexanamide

6NIC の概要

• エントリーDOI: 10.2210/pdb6nic/pdb
• 分子名称: Porphyromonas-type peptidyl-arginine deiminase, TRIETHYLENE GLYCOL, 6-aminohexanamide, ... (7 entities in total)
• 機能のキーワード: polyamine metabolism, putrescine biosynthesis, hydrolase
• 由来する生物種: Medicago truncatula (Barrel medic)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 166221.71

構造登録者

Sekula, B.,Dauter, Z. (登録日: 2018-12-27, 公開日: 2019-03-20, 最終更新日: 2023-10-11)

主引用文献

Sekula, B.,Dauter, Z.
Structural Study of Agmatine Iminohydrolase FromMedicago truncatula, the Second Enzyme of the Agmatine Route of Putrescine Biosynthesis in Plants.
Front Plant Sci, 10:320-320, 2019

PubMed Abstract: Plants are unique eukaryotes that can produce putrescine (PUT), a basic diamine, from arginine a three-step pathway. This process starts with arginine decarboxylase that converts arginine to agmatine. Then, the consecutive action of two hydrolytic enzymes, agmatine iminohydrolase (AIH) and carbamoylputrescine amidohydrolase, ultimately produces PUT. An alternative route of PUT biosynthesis requires ornithine decarboxylase that catalyzes direct putrescine biosynthesis. However, some plant species lack this enzyme and rely only on agmatine pathway. The scope of this manuscript concerns the structural characterization of AIH from the model legume plant, . AIH is a homodimer built of two subunits with a characteristic propeller fold, where five αββαβ repeated units are arranged around the fivefold pseudosymmetry axis. Dimeric assembly of this plant AIH, formed by interactions of conserved structural elements from one repeat, is drastically different from that observed in dimeric bacterial AIHs. Additionally, the structural snapshot of AIH in complex with 6-aminohexanamide, the reaction product analog, presents the conformation of the enzyme during catalysis. Our structural results show that AIH undergoes significant structural rearrangements of the long loop, which closes a tunnel-shaped active site over the course of the catalytic event. This conformational change is also observed in AIH from , indicating the importance of the closed conformation of the gate-keeping loop for the catalysis of plant AIHs.

PubMed: 30984210
DOI: 10.3389/fpls.2019.00320

実験手法

X-RAY DIFFRACTION (2.2 Å)