5xfr | pdb_00005xfr
Ternary complex of MTF2, DNA and histone
Structural highlights
FunctionMTF2_HUMAN Polycomb group (PcG) that specifically binds histone H3 trimethylated at 'Lys-36' (H3K36me3) and recruits the PRC2 complex. Acts by binding to H3K36me3, a mark for transcriptional activation, and recruiting the PRC2 complex, leading to enhance PRC2 H3K27me3 methylation activity. Regulates the transcriptional networks during embryonic stem cell self-renewal and differentiation. Promotes recruitment of the PRC2 complex to the inactive X chromosome in differentiating XX ES cells and PRC2 recruitment to target genes in undifferentiated ES cells. Required to repress Hox genes by enhancing H3K27me3 methylation of the PRC2 complex. In some conditions may act as an inhibitor of PRC2 activity: able to activate the CDKN2A gene and promote cellular senescence by suppressing the catalytic activity of the PRC2 complex locally. Binds to the metal-regulating-element (MRE) of MT1A gene promoter (By similarity). Publication Abstract from PubMedThe Polycomb repressive complex 2 (PRC2) mainly mediates transcriptional repression and has essential roles in various biological processes including the maintenance of cell identity and proper differentiation. Polycomb-like (PCL) proteins, such as PHF1, MTF2 and PHF19, are PRC2-associated factors that form sub-complexes with PRC2 core components, and have been proposed to modulate the enzymatic activity of PRC2 or the recruitment of PRC2 to specific genomic loci. Mammalian PRC2-binding sites are enriched in CG content, which correlates with CpG islands that display a low level of DNA methylation. However, the mechanism of PRC2 recruitment to CpG islands is not fully understood. Here we solve the crystal structures of the N-terminal domains of PHF1 and MTF2 with bound CpG-containing DNAs in the presence of H3K36me3-containing histone peptides. We show that the extended homologous regions of both proteins fold into a winged-helix structure, which specifically binds to the unmethylated CpG motif but in a completely different manner from the canonical winged-helix DNA recognition motif. We also show that the PCL extended homologous domains are required for efficient recruitment of PRC2 to CpG island-containing promoters in mouse embryonic stem cells. Our research provides the first, to our knowledge, direct evidence to demonstrate that PCL proteins are crucial for PRC2 recruitment to CpG islands, and further clarifies the roles of these proteins in transcriptional regulation in vivo. Polycomb-like proteins link the PRC2 complex to CpG islands.,Li H, Liefke R, Jiang J, Kurland JV, Tian W, Deng P, Zhang W, He Q, Patel DJ, Bulyk ML, Shi Y, Wang Z Nature. 2017 Sep 14;549(7671):287-291. doi: 10.1038/nature23881. Epub 2017 Sep 6. PMID:28869966[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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