Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China.
Acta Crystallogr F Struct Biol Commun. 2021 Jan 1;77(Pt 1):8-12. doi: 10.1107/S2053230X20016398.
Plant nucleotide-binding domain and leucine-rich repeat receptors (NLRs) play crucial roles in recognizing pathogen effectors and activating plant immunity. The tomato NLR Sw-5b is a coiled-coil NLR (CC-NLR) immune receptor that confers resistance against tospoviruses, which cause serious economic losses in agronomic crops worldwide. Compared with other CC-NLRs, Sw-5b possesses an extended N-terminal Solanaceae domain (SD). The SD of Sw-5b is critical for recognition of the tospovirus viral movement protein NSm. An SD is also frequently detected in many NLRs from Solanaceae plants. However, no sequences homologous to the SD have been detected in animals or in plants other than Solanaceae. The properties of the SD protein are largely unknown, and thus 3D structural information is vital in order to better understand its role in pathogen perception and the activation of immune receptors. Here, the expression, purification and crystallization of Sw-5b SD (amino acids 1-245) are reported. Native and selenomethionine-substituted crystals of the SD protein belonged to space group P312, with unit-cell parameters a = 81.53, b = 81.53, c = 98.44 Å and a = 81.63, b = 81.63, c = 98.80 Å, respectively. This is the first report of a structural study of the noncanonical SD domain of the NLR proteins from Solanaceae plants.
植物核苷酸结合域和富含亮氨酸重复受体（NLRs）在识别病原体效应子和激活植物免疫方面发挥着关键作用。番茄 NLR Sw-5b 是一种卷曲螺旋 NLR（CC-NLR）免疫受体，可抵抗引起全球农业作物严重经济损失的弹状病毒。与其他 CC-NLR 相比，Sw-5b 具有扩展的茄科 N 端结构域（SD）。Sw-5b 的 SD 对于识别弹状病毒病毒移动蛋白 NSm 至关重要。SD 也经常在茄科植物的许多 NLR 中检测到。然而，在动物或茄科以外的植物中，尚未检测到与 SD 同源的序列。SD 蛋白的性质在很大程度上是未知的，因此 3D 结构信息对于更好地理解其在病原体感知和免疫受体激活中的作用至关重要。本文报道了 Sw-5b SD（氨基酸 1-245）的表达、纯化和结晶。SD 蛋白的天然和硒代甲硫氨酸取代晶体属于 P312 空间群，具有单元晶胞参数 a = 81.53，b = 81.53，c = 98.44 Å 和 a = 81.63，b = 81.63，c = 98.80 Å。这是首次报道茄科植物 NLR 蛋白中非典型 SD 结构域的结构研究。
