1pfb
From Proteopedia
|
Structural Basis for specific binding of polycomb chromodomain to histone H3 methylated at K27
Overview
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.
About this Structure
1PFB is a Protein complex structure of sequences from Drosophila melanogaster with , and as ligands. Full crystallographic information is available from OCA.
Reference
Structural basis for specific binding of Polycomb chromodomain to histone H3 methylated at Lys 27., Min J, Zhang Y, Xu RM, Genes Dev. 2003 Aug 1;17(15):1823-8. PMID:12897052
Page seeded by OCA on Thu Feb 21 14:28:15 2008
Categories: Drosophila melanogaster | Protein complex | Min, J R. | Xu, R M. | Zhang, Y. | ACY | BME | CL | Chromatin | Chromodomain | Histone methylation | Polycomb
