1PFB

Structural Basis for specific binding of polycomb chromodomain to histone H3 methylated at K27

Summary for 1PFB

• Entry DOI: 10.2210/pdb1pfb/pdb
• Descriptor: Polycomb protein, Histone H3, embryonic, CHLORIDE ION, ... (6 entities in total)
• Functional Keywords: chromatin, histone methylation, polycomb, chromodomain, peptide binding protein
• Biological source: Drosophila melanogaster (fruit fly); More
• Cellular location: Nucleus : P26017 P06352
• Total number of polymer chains: 2
• Total formula weight: 8174.33

Authors

Min, J.R.,Zhang, Y.,Xu, R.-M. (deposition date: 2003-05-24, release date: 2003-10-07, Last modification date: 2025-03-26)

Primary citation

Min, J.R.,Zhang, Y.,Xu, R.-M.
Structural basis for specific binding of Polycomb chromodomain to histone H3 methylated at Lys 27.
Genes Dev., 17:1823-1828, 2003

PubMed Abstract: The chromodomain of Drosophila Polycomb protein is essential for maintaining the silencing state of homeotic genes during development. Recent studies suggest that Polycomb mediates the assembly of repressive higher-order chromatin structures in conjunction with the methylation of Lys 27 of histone H3 by a Polycomb group repressor complex. A similar mechanism in heterochromatin assembly is mediated by HP1, a chromodomain protein that binds to histone H3 methylated at Lys 9. To understand the molecular mechanism of the methyl-Lys 27 histone code recognition, we have determined a 1.4-A-resolution structure of the chromodomain of Polycomb in complex with a histone H3 peptide trimethylated at Lys 27. The structure reveals a conserved mode of methyl-lysine binding and identifies Polycomb-specific interactions with histone H3. The structure also reveals a dPC dimer in the crystal lattice that is mediated by residues specifically conserved in the Polycomb family of chromodomains. The dimerization of dPC can effectively account for the histone-binding specificity and provides new mechanistic insights into the function of Polycomb. We propose that self-association is functionally important for Polycomb.

PubMed: 12897052
DOI: 10.1101/gad.269603

Experimental method

X-RAY DIFFRACTION (1.4 Å)