1TI5

Solution structure of plant defensin

1TI5 の概要

• エントリーDOI: 10.2210/pdb1ti5/pdb
• 分子名称: plant defensin (1 entity in total)
• 機能のキーワード: defensin, insecticidal activity, mung bean, plant protein
• 由来する生物種: Vigna radiata
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 5131.15

構造登録者

Liu, Y.J.,Cheng, C.S.,Liu, Y.N.,Hsu, M.P.,Chen, C.S.,Lyu, P.C. (登録日: 2004-06-02, 公開日: 2005-07-26, 最終更新日: 2024-11-13)

主引用文献

Liu, Y.J.,Cheng, C.S.,Lai, S.M.,Hsu, M.P.,Chen, C.S.,Lyu, P.C.
Solution structure of the plant defensin VrD1 from mung bean and its possible role in insecticidal activity against bruchids.
Proteins, 63:777-786, 2006

PubMed Abstract: Vigna radiata plant defensin 1 (VrD1) is the first reported plant defensin exhibiting insecticidal activity. We report herein the nuclear magnetic resonance solution structure of VrD1 and the implication on its insecticidal activity. The root-mean-square deviation values are 0.51 +/- 0.35 and 1.23 +/- 0.29 A for backbone and all heavy atoms, respectively. The VrD1 structure comprises a triple-stranded antiparallel beta-sheet, an alpha-helix, and a 3(10) helix stabilized by four disulfide bonds, forming a typical cysteine-stabilized alphabeta motif. Among plant defensins of known structure, VrD1 is the first to contain a 3(10) helix. Glu26 is highly conserved among defensins; VrD1 contains an arginine at this position, which may induce a shift in the orientation of Trp10, thereby promoting the formation of this 3(10) helix. Moreover, VrD1 inhibits Tenebrio molitor alpha-amylase. Alpha-amylase has an essential role in the digestion of plant starch in the insect gut, and expression of the common bean alpha-amylase inhibitor 1 in transgenic pea imparts complete resistance against bruchids. These results imply that VrD1 insecticidal activity has its basis in the inhibition of a polysaccharide hydrolase. Sequence and structural comparisons between two groups of plant defensins having different specificity toward insect alpha-amylase reveal that the loop between beta2 and beta3 is the probable binding site for the alpha-amylase. Computational docking experiments were used to study VrD1-alpha-amylase interactions, and these results provide information that may be used to improve the insecticidal activity of VrD1.

PubMed: 16544327
DOI: 10.1002/prot.20962

実験手法

SOLUTION NMR