7XPJ

crystal structure of rice ASI1 BAH domain

Summary for 7XPJ

• Entry DOI: 10.2210/pdb7xpj/pdb
• Descriptor: BAH domain-containing protein (2 entities in total)
• Functional Keywords: bah domain, asi1, rice, suvh6, h3k9me2 deposition, gene regulation
• Biological source: Oryza sativa Japonica Group (Japanese rice)
• Total number of polymer chains: 1
• Total formula weight: 18799.53

Authors

Yuan, J.,Du, J. (deposition date: 2022-05-04, release date: 2023-01-11, Last modification date: 2023-11-29)

Primary citation

Zhang, J.,Yuan, J.,Lin, J.,Chen, L.,You, L.Y.,Chen, S.,Peng, L.,Wang, C.H.,Du, J.,Duan, C.G.
Molecular basis of locus-specific H3K9 methylation catalyzed by SUVH6 in plants.
Proc.Natl.Acad.Sci.USA, 120:e2208525120-e2208525120, 2023

PubMed Abstract: Dimethylated histone H3 Lys9 (H3K9me2) is a conserved heterochromatic mark catalyzed by SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG (SUVH) methyltransferases in plants. However, the mechanism underlying the locus specificity of SUVH enzymes has long been elusive. Here, we show that a conserved N-terminal motif is essential for SUVH6-mediated H3K9me2 deposition in planta. The SUVH6 N-terminal peptide can be recognized by the bromo-adjacent homology (BAH) domain of the RNA- and chromatin-binding protein ANTI-SILENCING 1 (ASI1), which has been shown to function in a complex to confer gene expression regulation. Structural data indicate that a classic aromatic cage of ASI1-BAH domain specifically recognizes an arginine residue of SUVH6 through extensive hydrogen bonding interactions. A classic aromatic cage of ASI1 specifically recognizes an arginine residue of SUVH6 through extensive cation-π interactions, playing a key role in recognition. The SUVH6-ASI1 module confers locus-specific H3K9me2 deposition at most SUVH6 target loci and gives rise to distinct regulation of gene expression depending on the target loci, either conferring transcriptional silencing or posttranscriptional processing of mRNA. More importantly, such mechanism is conserved in multiple plant species, indicating a coordinated evolutionary process between SUVH6 and ASI1. In summary, our findings uncover a conserved mechanism for the locus specificity of H3K9 methylation in planta. These findings provide mechanistic insights into the delicate regulation of H3K9 methylation homeostasis in plants.

PubMed: 36580600
DOI: 10.1073/pnas.2211155120

Experimental method

X-RAY DIFFRACTION (2.301 Å)