Molecular basis of PRC1 targeting to Polycomb response elements by PhoRC
Research output: Contribution to journal › Journal article › Research › peer-review
Polycomb group (PcG) protein complexes repress transcription by modifying target gene chromatin. In Drosophila, this repression requires association of PcG protein complexes with cis-regulatory Polycomb response elements (PREs), but the interactions permitting formation of these assemblies are poorly understood. We show that the Sfmbt subunit of the DNA-binding Pho-repressive complex (PhoRC) and the Scm subunit of the canonical Polycomb-repressive complex 1 (PRC1) directly bind each other through their SAM domains. The 1.9 Å crystal structure of the Scm-SAM:Sfmbt-SAM complex reveals the recognition mechanism and shows that Sfmbt-SAM lacks the polymerization capacity of the SAM domains of Scm and its PRC1 partner subunit, Ph. Functional analyses in Drosophila demonstrate that Sfmbt-SAM and Scm-SAM are essential for repression and that PhoRC DNA binding is critical to initiate PRC1 association with PREs. Together, this suggests that PRE-tethered Sfmbt-SAM nucleates PRC1 recruitment and that Scm-SAM/Ph-SAM-mediated polymerization then results in the formation of PRC1-compacted chromatin.
Original language | English |
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Journal | Genes & Development |
Volume | 30 |
Issue number | 9 |
Pages (from-to) | 1116-27 |
Number of pages | 12 |
ISSN | 0890-9369 |
DOIs | |
Publication status | Published - 1 May 2016 |
Externally published | Yes |
- Animals, Chromatin, Crystallography, Drosophila Proteins, Drosophila melanogaster, Gene Expression Regulation, Models, Molecular, Polycomb Repressive Complex 1, Polycomb-Group Proteins, Polymerization, Protein Binding, Protein Structure, Tertiary, Response Elements, Journal Article
Research areas
ID: 186876710