3g7l | pdb_00003g7l
Chromodomain of Chp1 in complex with Histone H3K9me3 peptide
Structural highlights
FunctionCHP1_SCHPO Component of the kinetochore which plays a role in stabilizing microtubules and so allowing accurate chromosome segregation. Has a role in the RNA interference (RNAi) pathway which is important for heterochromatin formation and accurate chromosome segregation. A member of the RNA-induced transcriptional silencing (RITS) complex which is involved in the biosynthesis of dsRNA from primer siRNAs provided by the RNA-directed RNA polymerase (RDRC) complex.[1] [2] [3] [4] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn fission yeast, assembly of centromeric heterochromatin requires the RITS complex, which consists of Ago1, Tas3, Chp1, and siRNAs derived from centromeric repeats. Recruitment of RITS to centromeres has been proposed to depend on siRNA-dependent targeting of Ago1 to centromeric sequences. Previously, we demonstrated that methylated lysine 9 of histone H3 (H3K9me) acts upstream of siRNAs during heterochromatin establishment. Our crystal structure of Chp1's chromodomain in complex with a trimethylated lysine 9 H3 peptide reveals extensive sites of contact that contribute to Chp1's high-affinity binding. We found that this high-affinity binding is critical for the efficient establishment of centromeric heterochromatin, but preassembled heterochromatin can be maintained when Chp1's affinity for H3K9me is greatly reduced. High-affinity binding of Chp1 chromodomain to K9 methylated histone H3 is required to establish centromeric heterochromatin.,Schalch T, Job G, Noffsinger VJ, Shanker S, Kuscu C, Joshua-Tor L, Partridge JF Mol Cell. 2009 Apr 10;34(1):36-46. PMID:19362535[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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