Weiss M S, Anderson D H, Raffioni S, Bradshaw R A, Ortenzi C, Luporini P, Eisenberg D
Molecular Biology Institute, University of California, Los Angeles 90095-1570, USA.
Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10172-6. doi: 10.1073/pnas.92.22.10172.
The crystal structure of the pheromone Er-1 from the unicellular eukaryotic organism Euplotes raikovi was determined at 1.6 A resolution and refined to a crystallographic R factor of 19.9%. In the tightly packed crystal, two extensive intermolecular helix-helix interactions arrange the Er-1 molecules into layers. Since the putative receptor of the pheromone is a membrane-bound protein, whose extracellular C-terminal domain is identical in amino acid sequence to the soluble pheromone, the interactions found in the crystal may mimic the pheromone-receptor interactions as they occur on a cell surface. Based on this, we propose a model for the interaction between soluble pheromone molecules and their receptors. In this model, strong pheromone-receptor binding emerges as a consequence of the cooperative utilization of several weak interactions. The model offers an explanation for the results of binding studies and may also explain the adhesion between cells that occurs during mating.
单细胞真核生物雷氏游仆虫（Euplotes raikovi）的信息素Er-1的晶体结构在1.6埃分辨率下得以确定，并精修至晶体学R因子为19.9%。在紧密堆积的晶体中，两种广泛的分子间螺旋-螺旋相互作用将Er-1分子排列成层。由于该信息素的假定受体是一种膜结合蛋白，其细胞外C末端结构域在氨基酸序列上与可溶性信息素相同，因此晶体中发现的相互作用可能模拟了细胞表面发生的信息素-受体相互作用。基于此，我们提出了一个可溶性信息素分子与其受体之间相互作用的模型。在该模型中，强信息素-受体结合是几种弱相互作用协同作用的结果。该模型为结合研究的结果提供了解释，也可能解释交配过程中细胞间发生的黏附现象。
