WRKY結構域是一類轉錄因子，存在於WRKY轉錄因子家族中[1]。幾乎所有植物基因組中都有帶WRKY結構域的蛋白，同時WRKY基因也被發現存在於雙滴蟲、多細胞變形蟲及其他變形蟲門和一些真菌基因組中。不過WRKY基因似乎不存在於一些其他的非植物物種。在過去的20年間，WRKY轉錄因子一直是植物學領域的重點研究對象[2]。WRKY的DNA識別結構域能夠識別W-box順式作用元件(T)TGAC(C/T)，以及W-box序列的一些變體。
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WRKY轉錄因子含有一個或兩個WRKY蛋白結構域。 WRKY蛋白結構域是一個長度為60到70個氨基酸的DNA結合結構域。該結構域的主要特徵是一個高度保守的WRKYGQK模序和一個鋅指區域。 半胱氨酸和組氨酸鋅指結構域是CX4-5CX22-23HXH或CX7CX23HXC類型的，其中X可以是任何氨基酸。 [3]鋅指結合Zn2+離子來滿足蛋白質功能的需要。[4]儘管WRKYGQK序列在大多數WRKY結構域中是高度保守的，但是也有文獻記載核心序列是存在差異化的。 [5]核心序列的一種常見的變體是WRKYGKK，存在於大多數植物物種中。[6]
WRKY蛋白結構域的結構由2005年的核磁共振（NMR）和後來的結晶學所確定。[7]WRKY蛋白結構域是由五條反平行β-鏈組成的球形蛋白。核心的WRKYGQK模序位於第二個β鏈上。[8]18個氨基酸在WRKY蛋白結構域中是高度保守的，包括核心基序，鋅指結合的半胱氨酸和組氨酸和形成DWK鹽橋的三聯體。[8]三聯體由位於核心模序的保守色氨酸（W）、四個氨基酸前的天冬氨酸（D）和29個氨基酸後的賴氨酸（K）組成，這個組合穩定了整個結構域。[8]第三個β-鏈上的五個氨基酸（PRSYY）在WRKY結構域中也很保守。[8]重要的是，WRKY基因在WRKY結構域中含有一個保守的內含子，它發生在編碼PRSYY氨基酸序列PR的位置。[3]這就解釋了該基序的保守性。
WRKY結構域形成了一個垂直進入DNA鏈的主溝的獨特楔形結構。 [9]WRKY蛋白結構域與（T / A）TGAC（T / A）順式元件（也稱為W-Box）存在着相互作用。[10]最近的證據表明，W-Box的GAC核心是WRKY結構域的主要作用位點，側翼序列有助於調控DNA與特異性的WRKY蛋白之間的相互作用。[11]核心模序的RKYGQK殘基和WRKY結構域中的精氨酸與賴氨酸殘基負責與七個連續DNA鹼基對（包括GAC核心）的磷酸骨架相互作用。[12]將色氨酸，酪氨酸或WRKYGQK模序的賴氨酸突變為丙氨酸則會使蛋白無法與DNA結合，這個情況表明這些氨基酸對於識別W-Box序列是必不可少的。[13]儘管不是必要的，當用丙氨酸突變掉WRKYGQK模序中的精氨酸，甘氨酸或穀氨酰胺時，可以減少與W-Box的結合。[13]總的來說，WRKY蛋白結構域與DNA的複雜的相互作用會在植物生長發育和抵抗外界脅迫時，起到激活有關基因的作用。
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Yamasaki, Kigawa, Inoue, Tateno, Yamasaki, et al. (2005) Solution Structure of an Arabidopsis WRKY DNA Binding Domain. The Plant Cell. 17(3). 944-956, Duan, Nan, Liang, Mao, Lu, et al. (2007) DNA binding mechanism revealed by high resolution crystal structure of Arabidopsis thaliana WRKY1 protein. Nucleic Acids Research. 35(4). 1145-1154
Duan, Nan, Liang, Mao, Lu, et al. (2007) DNA binding mechanism revealed by high resolution crystal structure of Arabidopsis thaliana WRKY1 protein. Nucleic Acids Research. 35(4). 1145-1154
Yamasaki, Kigawa, Watanabe, Inoue, Yamasaki, et al. (2012) Structural Basis for Sequence-specific DNA Recognition by an Arabidopsis WRKY Transcription Factor. Journal of Biological Chemistry. 287(10). 7683-7691
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Yamasaki, Kigawa, Watanabe, Inoue, Yamasaki, et al. (2012) Structural Basis for Sequence-specific DNA Recognition by an Arabidopsis WRKY Transcription Factor. Journal of Biological Chemistry. 287(10). 7683-7691, Brand, Fischer, Harter, Kohlbacher and Wanke (2013) Elucidating the evolutionary conserved DNA-binding specificities of WRKY transcription factors by molecular dynamics and in vitro binding assays. Nucleic Acids Research. 41(21). 9764-9778
Duan, Nan, Liang, Mao, Lu, et al. (2007) DNA binding mechanism revealed by high resolution crystal structure of Arabidopsis thaliana WRKY1 protein. Nucleic Acids Research. 35(4). 1145-1154, Maeo, Hayashi, Kojima-Suzuki, Morikami and Nakamura (2001) Role of conserved residues of the WRKY domain in the DNA-binding of tobacco WRKY family proteins. Bioscience, Biotechnology, and Biochemistry. 65(11). 2428-2436
