1MR4

Solution Structure of NaD1 from Nicotiana alata

1MR4 の概要

• エントリーDOI: 10.2210/pdb1mr4/pdb
• 分子名称: Nicotiana alata plant defensin 1 (NaD1) (1 entity in total)
• 機能のキーワード: cysteine-stabilized alpha-beta motif, plant defensin fold, plant protein
• 由来する生物種: Nicotiana tabacum (common tobacco)
• 細胞内の位置: Secreted, cell wall (By similarity): P32026
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 5315.38

構造登録者

Lay, F.T.,Schirra, H.J.,Scanlon, M.J.,Anderson, M.A.,Craik, D.J. (登録日: 2002-09-18, 公開日: 2003-09-18, 最終更新日: 2024-10-23)

主引用文献

Lay, F.T.,Schirra, H.J.,Scanlon, M.J.,Anderson, M.A.,Craik, D.J.
The Three-dimensional Solution Structure of NaD1, a New Floral Defensin from Nicotiana alata and its Application to a Homology Model of the Crop Defense Protein alfAFP
J.MOL.BIOL., 325:175-188, 2003

PubMed Abstract: NMR spectroscopy and simulated annealing calculations have been used to determine the three-dimensional structure of NaD1, a novel antifungal and insecticidal protein isolated from the flowers of Nicotiana alata. NaD1 is a basic, cysteine-rich protein of 47 residues and is the first example of a plant defensin from flowers to be characterized structurally. Its three-dimensional structure consists of an alpha-helix and a triple-stranded antiparallel beta-sheet that are stabilized by four intramolecular disulfide bonds. NaD1 features all the characteristics of the cysteine-stabilized alphabeta motif that has been described for a variety of proteins of differing functions ranging from antibacterial insect defensins and ion channel-perturbing scorpion toxins to an elicitor of the sweet taste response. The protein is biologically active against insect pests, which makes it a potential candidate for use in crop protection. NaD1 shares 31% sequence identity with alfAFP, an antifungal protein from alfalfa that confers resistance to a fungal pathogen in transgenic potatoes. The structure of NaD1 was used to obtain a homology model of alfAFP, since NaD1 has the highest level of sequence identity with alfAFP of any structurally characterized antifungal defensin. The structures of NaD1 and alfAFP were used in conjunction with structure-activity data for the radish defensin Rs-AFP2 to provide an insight into structure-function relationships. In particular, a putative effector site was identified in the structure of NaD1 and in the corresponding homology model of alfAFP.

PubMed: 12473460
DOI: 10.1016/S0022-2836(02)01103-8

実験手法

SOLUTION NMR