5WXU

11S globulin from Wrightia tinctoria reveals auxin binding site

5WXU の概要

• エントリーDOI: 10.2210/pdb5wxu/pdb
• 分子名称: 11S globulin, PHOSPHATE ION, CITRATE ANION, ... (7 entities in total)
• 機能のキーワード: auxin natural source, plant protein
• 由来する生物種: Wrightia tinctoria
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 327614.77

構造登録者

Kumar, P.,Kesari, P.,Dhindwal, S.,Kumar, P. (登録日: 2017-01-09, 公開日: 2018-05-23, 最終更新日: 2024-10-16)

主引用文献

Kumar, P.,Kesari, P.,Dhindwal, S.,Choudhary, A.K.,Katiki, M.,Verma, A.,Ambatipudi, K.,Tomar, S.,Sharma, A.K.,Mishra, G.,Kumar, P.
A novel function for globulin in sequestering plant hormone: Crystal structure of Wrightia tinctoria 11S globulin in complex with auxin.
Sci Rep, 7:4705-4705, 2017

PubMed Abstract: Auxin levels are tightly regulated within the plant cell, and its storage in the isolated cavity of proteins is a measure adopted by cells to maintain the availability of auxin. We report the first crystal structure of Wrightia tinctoria 11S globulin (WTG) in complex with Indole-3-acetic acid (IAA), an auxin, at 1.7 Å resolution. WTG hexamers assemble as a result of the stacking interaction between the hydrophobic surfaces of two trimers, leaving space for the binding of charged ligands. The bound auxin is stabilized by non-covalent interactions, contributed by four chains in each cavity. The presence of bound ligand was confirmed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and high-resolution mass spectrometry (HRMS). Here, we hypothesize that the cleavage of globulins by endopeptidases leads to the movement of the hydrophilic loop region from the surface to the periphery, leaving space for the binding of auxin, and promotes hexamer formation. As the process of germination proceeds, there is a change in the pH, which induces the dissociation of the hexamer and the release of auxin. The compact hexameric assembly ensures the long-term, stable storage of the hormone. This suggests a role for globulin as a novel player in auxin homeostasis.

PubMed: 28680092
DOI: 10.1038/s41598-017-04518-7

実験手法

X-RAY DIFFRACTION (1.7 Å)