1TI5
Solution structure of plant defensin
Summary for 1TI5
| Entry DOI | 10.2210/pdb1ti5/pdb |
| Descriptor | plant defensin (1 entity in total) |
| Functional Keywords | defensin, insecticidal activity, mung bean, plant protein |
| Biological source | Vigna radiata |
| Total number of polymer chains | 1 |
| Total formula weight | 5131.15 |
| Authors | Liu, Y.J.,Cheng, C.S.,Liu, Y.N.,Hsu, M.P.,Chen, C.S.,Lyu, P.C. (deposition date: 2004-06-02, release date: 2005-07-26, Last modification date: 2022-03-02) |
| Primary citation | 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 Cited by 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: 16544327DOI: 10.1002/prot.20962 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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