4PZO

Crystal structure of PHC3 SAM L967R

4PZO の概要

• エントリーDOI: 10.2210/pdb4pzo/pdb
• 関連するPDBエントリー: 4PZN
• 分子名称: Polyhomeotic-like protein 3 (2 entities in total)
• 機能のキーワード: sam domain, polycomb group, polymer, chromatin, dna binding protein
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Nucleus : Q8NDX5
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 57419.93

構造登録者

Nanyes, D.R.,Junco, S.E.,Taylor, A.B.,Robinson, A.K.,Patterson, N.L.,Shivarajpur, A.,Halloran, J.,Hale, S.M.,Kaur, Y.,Hart, P.J.,Kim, C.A. (登録日: 2014-03-31, 公開日: 2014-07-30, 最終更新日: 2024-10-30)

主引用文献

Nanyes, D.R.,Junco, S.E.,Taylor, A.B.,Robinson, A.K.,Patterson, N.L.,Shivarajpur, A.,Halloran, J.,Hale, S.M.,Kaur, Y.,Hart, P.J.,Kim, C.A.
Multiple polymer architectures of human polyhomeotic homolog 3 sterile alpha motif.
Proteins, 82:2823-2830, 2014

PubMed Abstract: The self-association of sterile alpha motifs (SAMs) into a helical polymer architecture is a critical functional component of many different and diverse array of proteins. For the Drosophila Polycomb group (PcG) protein Polyhomeotic (Ph), its SAM polymerization serves as the structural foundation to cluster multiple PcG complexes, helping to maintain a silenced chromatin state. Ph SAM shares 64% sequence identity with its human ortholog, PHC3 SAM, and both SAMs polymerize. However, in the context of their larger protein regions, PHC3 SAM forms longer polymers compared with Ph SAM. Motivated to establish the precise structural basis for the differences, if any, between Ph and PHC3 SAM, we determined the crystal structure of the PHC3 SAM polymer. PHC3 SAM uses the same SAM-SAM interaction as the Ph SAM sixfold repeat polymer. Yet, PHC3 SAM polymerizes using just five SAMs per turn of the helical polymer rather than the typical six per turn observed for all SAM polymers reported to date. Structural analysis suggested that malleability of the PHC3 SAM would allow formation of not just the fivefold repeat structure but also possibly others. Indeed, a second PHC3 SAM polymer in a different crystal form forms a sixfold repeat polymer. These results suggest that the polymers formed by PHC3 SAM, and likely others, are dynamic. The functional consequence of the variable PHC3 SAM polymers may be to create different chromatin architectures.

PubMed: 25044168
DOI: 10.1002/prot.24645

実験手法

X-RAY DIFFRACTION (2.25 Å)