1XKL

Crystal Structure of Salicylic Acid-binding Protein 2 (SABP2) from Nicotiana tabacum, NESG Target AR2241

1XKL の概要

• エントリーDOI: 10.2210/pdb1xkl/pdb
• 分子名称: salicylic acid-binding protein 2, 2-AMINO-4H-1,3-BENZOXATHIIN-4-OL (3 entities in total)
• 機能のキーワード: alpha-beta protein, structural genomics, protein structure initiative, psi, northeast structural genomics consortium, nesg, unknown function
• 由来する生物種: Nicotiana tabacum (common tobacco)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 125942.92

構造登録者

Forouhar, F.,Chen, Y.,Chiang, Y.,Acton, T.B.,Montelione, G.T.,Hunt, J.F.,Tong, L.,Northeast Structural Genomics Consortium (NESG) (登録日: 2004-09-29, 公開日: 2004-11-30, 最終更新日: 2024-10-16)

主引用文献

Forouhar, F.,Yang, Y.,Kumar, D.,Chen, Y.,Fridman, E.
Structural and biochemical studies identify tobacco SABP2 as a methyl salicylate esterase and implicate it in plant innate immunity
Proc.Natl.Acad.Sci.USA, 102:1773-1778, 2005

PubMed Abstract: Salicylic acid (SA) is a critical signal for the activation of plant defense responses against pathogen infections. We recently identified SA-binding protein 2 (SABP2) from tobacco as a protein that displays high affinity for SA and plays a crucial role in the activation of systemic acquired resistance to plant pathogens. Here we report the crystal structures of SABP2, alone and in complex with SA at up to 2.1-A resolution. The structures confirm that SABP2 is a member of the alpha/beta hydrolase superfamily of enzymes, with Ser-81, His-238, and Asp-210 as the catalytic triad. SA is bound in the active site and is completely shielded from the solvent, consistent with the high affinity of this compound for SABP2. Our biochemical studies reveal that SABP2 has strong esterase activity with methyl salicylate as the substrate, and that SA is a potent product inhibitor of this catalysis. Modeling of SABP2 with MeSA in the active site is consistent with all these biochemical observations. Our results suggest that SABP2 may be required to convert MeSA to SA as part of the signal transduction pathways that activate systemic acquired resistance and perhaps local defense responses as well.

PubMed: 15668381
DOI: 10.1073/pnas.0409227102

実験手法

X-RAY DIFFRACTION (2 Å)