8kcb
Complex of DDM1-nucleosome(H2A) complex with DDM1 bound to SHL2
Structural highlights
FunctionH2A6_ARATH Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Required for the T-DNA integration step of plant transformation by Agrobacterium. May play an important role in illegitimate recombination.[1] [2] Publication Abstract from PubMedThe SWI/SNF2 chromatin remodeling factor decreased DNA methylation 1 (DDM1) is essential for the silencing of transposable elements (TEs) in both euchromatic and heterochromatic regions. Here, we determined the cryo-EM structures of DDM1-nucleosome(H2A) and DDM1-nucleosome(H2A.W) complexes at near-atomic resolution in the presence of the ATP analog ADP-BeFx. The structures show that nucleosomal DNA is unwrapped more on the surface of the histone octamer containing histone H2A than that containing histone H2A.W. DDM1 embraces one DNA gyre of the nucleosome and interacts with the N-terminal tails of histone H4. Although we did not observe DDM1-H2A.W interactions in our structures, the results of the pull-down experiments suggest a direct interaction between DDM1 and the core region of histone H2A.W. Our work provides mechanistic insights into the heterochromatin remodeling process driven by DDM1 in plants. Mechanism of heterochromatin remodeling revealed by the DDM1 bound nucleosome structures.,Zhang H, Gu Z, Zeng Y, Zhang Y Structure. 2024 Aug 8;32(8):1222-1230.e4. doi: 10.1016/j.str.2024.05.013. Epub , 2024 Jun 12. PMID:38870940[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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