ジャーナル: J Mol Biol / 年: 2012 タイトル: Structural insights on the plant salt-overly-sensitive 1 (SOS1) Na(+)/H(+) antiporter. 著者: Rafael Núñez-Ramírez / María José Sánchez-Barrena / Irene Villalta / Juan F Vega / Jose M Pardo / Francisco J Quintero / Javier Martinez-Salazar / Armando Albert / 要旨: The Arabidopsisthaliana Na(+)/H(+) antiporter salt-overly-sensitive 1 (SOS1) is essential to maintain low intracellular levels of toxic Na(+) under salt stress. Available data show that the plant ...The Arabidopsisthaliana Na(+)/H(+) antiporter salt-overly-sensitive 1 (SOS1) is essential to maintain low intracellular levels of toxic Na(+) under salt stress. Available data show that the plant SOS2 protein kinase and its interacting activator, the SOS3 calcium-binding protein, function together in decoding calcium signals elicited by salt stress and regulating the phosphorylation state and the activity of SOS1. Molecular genetic studies have shown that the activation implies a domain reorganization of the antiporter cytosolic moiety, indicating that there is a clear relationship between function and molecular structure of the antiporter. To provide information on this issue, we have carried out in vivo and in vitro studies on the oligomerization state of SOS1. In addition, we have performed electron microscopy and single-particle reconstruction of negatively stained full-length and active SOS1. Our studies show that the protein is a homodimer that contains a membrane domain similar to that found in other antiporters of the family and an elongated, large, and structured cytosolic domain. Both the transmembrane (TM) and cytosolic moieties contribute to the dimerization of the antiporter. The close contacts between the TM and the cytosolic domains provide a link between regulation and transport activity of the antiporter.
名称: Antiporter SOS1 / タイプ: sample / ID: 1000 詳細: This sample is a membrane protein and is purified with lipids and detergents surrounding the membrane domain 集合状態: Dimer / Number unique components: 1
分子量
実験値: 360 KDa / 理論値: 254 KDa 手法: Gel filtration, Electron microscopy image analysis, Dynamic light scattering
Single images of SOS1 were manually extracted using EMAN. 2D reference-free classification, 2D averaging, 3D classification and reconstruction were performed using maximum-likelihood methods implemented in XMIPP package.
CTF補正
詳細: Each micrograph. Estimation using CTFFIND3 and correction using Bsoft
最終 再構成
想定した対称性 - 点群: C2 (2回回転対称) / アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 25.9 Å / 解像度の算出法: FSC 0.5 CUT-OFF / ソフトウェア - 名称: XMIPP / 使用した粒子像数: 6300