Crystal structure of the leucine-rich repeat ectodomain of the plant immune receptor kinase SOBIR1
Crystal structure of the leucine-rich repeat ectodomain of the plant immune receptor kinase SOBIR1
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DOI：
10.1107/s2059798319005291
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发表时间：
2019-05-01
影响因子：
2.2
通讯作者：
Hothorn, Michael
中科院分区：
文献类型：
--
作者：
Hohmann, Ulrich;Hothorn, Michael
植物特有的富含亮氨酸重复序列(LRR)胞外区的膜受体蛋白是发育和免疫反应的关键调节因子。在这里，1.55埃分辨率的免疫受体激酶SOBIR1的晶体结构来自拟南芥。胞外结构揭示了夹在非正则封顶结构域之间的五个LRR的存在。二硫键稳定的N端帽具有不寻常的发夹结构。C-末端帽子具有高度正电荷的线性基序，在这种结构中发现很大程度上是无序的。尺寸排斥层析和直角光散射实验表明SOBIR1在溶液中为单体。Sobir LRR结构域内表面的一组高度保守的碱性残基以及LRR2中存在的遗传错义等位基因共同表明SOBIR1胞外结构域可能在植物免疫信号中介导蛋白质-蛋白质相互作用。
Plant-unique membrane receptor kinases with leucine-rich repeat (LRR) extracellular domains are key regulators of development and immune responses. Here, the 1.55 angstrom resolution crystal structure of the immune receptor kinase SOBIR1 from Arabidopsis is presented. The ectodomain structure reveals the presence of five LRRs sandwiched between noncanonical capping domains. The disulfide-bond-stabilized N-terminal cap harbours an unusual -hairpin structure. The C-terminal cap features a highly positively charged linear motif which was found to be largely disordered in this structure. Size-exclusion chromatography and right-angle light-scattering experiments suggest that SOBIR1 is a monomer in solution. The protruding -hairpin, a set of highly conserved basic residues at the inner surface of the SOBIR LRR domain and the presence of a genetic missense allele in LRR2 together suggest that the SOBIR1 ectodomain may mediate protein-protein interaction in plant immune signalling.