Teyra Joan, Huang Haiming, Jain Shobhit, Guan Xinyu, Dong Aiping, Liu Yanli, Tempel Wolfram, Min Jinrong, Tong Yufeng, Kim Philip M, Bader Gary D, Sidhu Sachdev S
The Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada.
The Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
Structure. 2017 Oct 3;25(10):1598-1610.e3. doi: 10.1016/j.str.2017.07.017. Epub 2017 Sep 7.
SH3 domains are protein modules that mediate protein-protein interactions in many eukaryotic signal transduction pathways. The majority of SH3 domains studied thus far act by binding to proline-rich sequences in partner proteins, but a growing number of studies have revealed alternative recognition mechanisms. We have comprehensively surveyed the specificity landscape of human SH3 domains in an unbiased manner using peptide-phage display and deep sequencing. Based on ∼70,000 unique binding peptides, we obtained 154 specificity profiles for 115 SH3 domains, which reveal that roughly half of the SH3 domains exhibit non-canonical specificities and collectively recognize a wide variety of peptide motifs, most of which were previously unknown. Crystal structures of SH3 domains with two distinct non-canonical specificities revealed novel peptide-binding modes through an extended surface outside of the canonical proline-binding site. Our results constitute a significant contribution toward a complete understanding of the mechanisms underlying SH3-mediated cellular responses.
SH3结构域是在许多真核信号转导途径中介导蛋白质-蛋白质相互作用的蛋白质模块。迄今为止研究的大多数SH3结构域通过与伴侣蛋白中富含脯氨酸的序列结合来发挥作用，但越来越多的研究揭示了其他识别机制。我们使用肽-噬菌体展示和深度测序以无偏见的方式全面调查了人类SH3结构域的特异性情况。基于约70,000个独特的结合肽，我们获得了115个SH3结构域的154个特异性图谱，这些图谱表明大约一半的SH3结构域表现出非典型特异性，并共同识别多种肽基序，其中大多数以前是未知的。具有两种不同非典型特异性的SH3结构域的晶体结构通过经典脯氨酸结合位点之外的扩展表面揭示了新的肽结合模式。我们的结果为全面理解SH3介导的细胞反应的潜在机制做出了重大贡献。
