Grégoire, S., Grégoire, J., Joshi, M., Capitani, S., Chow, S., Couture, J.F. (2025). Protocol for the purification and crystallization of the Drosophila melanogaster Cfp1[PHD] domain in complex with an H3K4me3 peptide.  STAR Protoc 6(1): 103649.

FBrf0261909

Research paper

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[PHD]). Here, we present a protocol for the purification and crystallization of the Drosophila melanogaster Cfp1[PHD] domain in complex with an H3K4me3 peptide (PDB: 9C0O). We describe steps for obtaining highly pure Cfp1[PHD] and diffraction-quality crystals. We then detail procedures for rapidly identifying crystals containing the H3K4me3-bound form of the Cfp1[PHD] domain. For complete details on the use and execution of this protocol, please refer to Grégoire et al.[1].

PMC11904489 (PMC) (EuropePMC)