The phytohormone ethylene is widely involved in many developmental processes and is a crucial regulator of defense responses against biotic and abiotic stresses in plants. Ethylene-responsive element binding protein, a member of the APETALA2/ethylene response factor (AP2/ERF) superfamily, is a transcription factor that regulates stress-responsive genes by recognizing a specific cis-acting element of target DNA. A previous study showed only the NMR structure of the AP2/ERF domain of AtERF100 in complex with a GCC box DNA motif. In this report, we determined the crystal structure of AtERF96 in complex with a GCC box at atomic resolution. We analyzed the binding residues of the conserved AP2/ERF domain in the DNA recognition sequence. In addition to the AP2/ERF domain, an N-terminal α-helix of AtERF96 participates in DNA interaction in the flanking region. We also demonstrated the structure of AtERF96 EDLL motif, a unique conserved motif in the group IX of AP2/ERF family, might involve in the transactivation of defense-related genes. Our study establishes the structural basis of the AtERF96 transcription factor in complex with the GCC box, as well as the DNA binding mechanisms of the N-terminal α-helix and AP2/ERF domain.

植物激素乙烯广泛参与许多发育过程，是植物抵抗生物和非生物胁迫的防御反应的关键调节剂。乙烯反应元件结合蛋白是APETALA2 /乙烯反应因子（AP2 / ERF）超家族的成员，是一种转录因子，通过识别特定的顺式来调节应激反应基因。靶DNA的-作用元件。先前的研究表明，只有AtERF100的AP2 / ERF结构域的NMR结构与GCC box DNA基序复合。在此报告中，我们以原子分辨率确定了带有GCC盒的AtERF96的晶体结构。我们分析了DNA识别序列中保守的AP2 / ERF域的结合残基。除AP2 / ERF域外，AtERF96的N末端α螺旋还参与侧翼区域的DNA相互作用。我们还证明了AtERF96 EDLL基序的结构，这是AP2 / ERF家族IX组中唯一的保守基序，可能与防御相关基因的反式激活有关。我们的研究建立了与GCC盒复合的AtERF96转录因子的结构基础，以及N末端α-螺旋和AP2 / ERF结构域的DNA结合机制。