3I90

Crystal structure of human chromobox homolog 6 (CBX6) with H3K27 peptide

3I90 の概要

• エントリーDOI: 10.2210/pdb3i90/pdb
• 関連するPDBエントリー: 3I8Y 3I8Z 3I91
• 分子名称: Chromobox protein homolog 6, H3K27 peptide (3 entities in total)
• 機能のキーワード: chromobox homolog 6, cbx6, h3k27 peptide, structural genomics, structural genomics consortium, sgc, chromatin regulator, nucleus, phosphoprotein, repressor, transcription, transcription regulation
• 由来する生物種: Homo sapiens (human); 詳細
• 細胞内の位置: Nucleus : O95503
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 14733.23

構造登録者

Amaya, M.F.,Ravichandran, M.,Loppnau, P.,Kozieradzki, I.,Edwards, A.M.,Arrowsmith, C.H.,Weigelt, J.,Bountra, C.,Bochkarev, A.,Min, J.,Ouyang, H.,Structural Genomics Consortium (SGC) (登録日: 2009-07-10, 公開日: 2009-09-08, 最終更新日: 2023-09-06)

主引用文献

Kaustov, L.,Ouyang, H.,Amaya, M.,Lemak, A.,Nady, N.,Duan, S.,Wasney, G.A.,Li, Z.,Vedadi, M.,Schapira, M.,Min, J.,Arrowsmith, C.H.
Recognition and specificity determinants of the human cbx chromodomains.
J.Biol.Chem., 286:521-529, 2011

PubMed Abstract: The eight mammalian Cbx proteins are chromodomain-containing proteins involved in regulation of heterochromatin, gene expression, and developmental programs. They are evolutionarily related to the Drosophila HP1 (dHP1) and Pc (dPc) proteins that are key components of chromatin-associated complexes capable of recognizing repressive marks such as trimethylated Lys-9 and Lys-27, respectively, on histone H3. However, the binding specificity and function of the human homologs, Cbx1-8, remain unclear. To this end we employed structural, biophysical, and mutagenic approaches to characterize the molecular determinants of sequence contextual methyllysine binding to human Cbx1-8 proteins. Although all three human HP1 homologs (Cbx1, -3, -5) replicate the structural and binding features of their dHP counterparts, the five Pc homologs (Cbx2, -4, -6, -7, -8) bind with lower affinity to H3K9me3 or H3K27me3 peptides and are unable to distinguish between these two marks. Additionally, peptide permutation arrays revealed a greater sequence tolerance within the Pc family and suggest alternative nonhistone sequences as potential binding targets for this class of chromodomains. Our structures explain the divergence of peptide binding selectivity in the Pc subfamily and highlight previously unrecognized features of the chromodomain that influence binding and specificity.

PubMed: 21047797
DOI: 10.1074/jbc.M110.191411

実験手法

X-RAY DIFFRACTION (2 Å)