7CCE

crystal structure of Arabidopsis AIPP3 BAH domain in complex with an H3K27me3 peptide

Summary for 7CCE

• Entry DOI: 10.2210/pdb7cce/pdb
• Descriptor: Bromo-adjacent homology (BAH) domain-containing protein, Histone H3.2, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL, ... (4 entities in total)
• Functional Keywords: bah domain, aipp3, h3k27me3, histone modification, epigenetcis, gene regulation
• Biological source: Arabidopsis thaliana (Mouse-ear cress); More
• Total number of polymer chains: 2
• Total formula weight: 21601.72

Authors

Yuan, J.,Du, J. (deposition date: 2020-06-17, release date: 2020-12-16, Last modification date: 2023-11-29)

Primary citation

Zhang, Y.Z.,Yuan, J.,Zhang, L.,Chen, C.,Wang, Y.,Zhang, G.,Peng, L.,Xie, S.S.,Jiang, J.,Zhu, J.K.,Du, J.,Duan, C.G.
Coupling of H3K27me3 recognition with transcriptional repression through the BAH-PHD-CPL2 complex in Arabidopsis.
Nat Commun, 11:6212-6212, 2020

PubMed Abstract: Histone 3 Lys 27 trimethylation (H3K27me3)-mediated epigenetic silencing plays a critical role in multiple biological processes. However, the H3K27me3 recognition and transcriptional repression mechanisms are only partially understood. Here, we report a mechanism for H3K27me3 recognition and transcriptional repression. Our structural and biochemical data showed that the BAH domain protein AIPP3 and the PHD proteins AIPP2 and PAIPP2 cooperate to read H3K27me3 and unmodified H3K4 histone marks, respectively, in Arabidopsis. The BAH-PHD bivalent histone reader complex silences a substantial subset of H3K27me3-enriched loci, including a number of development and stress response-related genes such as the RNA silencing effector gene ARGONAUTE 5 (AGO5). We found that the BAH-PHD module associates with CPL2, a plant-specific Pol II carboxyl terminal domain (CTD) phosphatase, to form the BAH-PHD-CPL2 complex (BPC) for transcriptional repression. The BPC complex represses transcription through CPL2-mediated CTD dephosphorylation, thereby causing inhibition of Pol II release from the transcriptional start site. Our work reveals a mechanism coupling H3K27me3 recognition with transcriptional repression through the alteration of Pol II phosphorylation states, thereby contributing to our understanding of the mechanism of H3K27me3-dependent silencing.

PubMed: 33277495
DOI: 10.1038/s41467-020-20089-0

Experimental method

X-RAY DIFFRACTION (2.404 Å)