Grégoire Sabrina, Grégoire Janelle, Joshi Monika, Capitani Sabrina, Chow Sara, Couture Jean-François
Ottawa Institute of Systems Biology, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
Ottawa Institute of Systems Biology, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
STAR Protoc. 2025 Mar 21;6(1):103649. doi: 10.1016/j.xpro.2025.103649. Epub 2025 Feb 21.
The tri-methylation of histone H3 on K4 (H3K4me3) is a key epigenetic modification that is predominantly found at active gene promoters and is deposited by the complex of proteins associated with SET1 (COMPASS). CXXC zinc finger protein 1 (Cfp1) regulates this process by recruiting SET1 to chromatin and recognizing H3K4me3 via its plant homeodomain (Cfp1). Here, we present a protocol for the purification and crystallization of the Drosophila melanogaster Cfp1 domain in complex with an H3K4me3 peptide (PDB: 9C0O). We describe steps for obtaining highly pure Cfp1 and diffraction-quality crystals. We then detail procedures for rapidly identifying crystals containing the H3K4me3-bound form of the Cfp1 domain. For complete details on the use and execution of this protocol, please refer to Grégoire et al..
组蛋白H3在赖氨酸4位点上的三甲基化（H3K4me3）是一种关键的表观遗传修饰，主要存在于活跃基因的启动子区域，由与SET1相关的蛋白质复合物（COMPASS）沉积。CXXC锌指蛋白1（Cfp1）通过将SET1招募到染色质上并通过其植物同源结构域识别H3K4me3来调节这一过程（Cfp1）。在此，我们展示了一种用于纯化和结晶与H3K4me3肽结合的果蝇Cfp1结构域的方法（蛋白质数据银行编号：9C0O）。我们描述了获得高纯度Cfp1和具有衍射质量晶体的步骤。然后，我们详细说明了快速鉴定含有与H3K4me3结合形式的Cfp1结构域的晶体的程序。有关此方法的使用和执行的完整详细信息，请参考格雷瓜尔等人的研究。
