5zoo
From Proteopedia
Crystal structure of histone deacetylase 4 (HDAC4) in complex with a SMRT corepressor SP1 fragment
Structural highlights
Disease[HDAC4_HUMAN] Defects in HDAC4 are the cause of brachydactyly-mental retardation syndrome (BDMR) [MIM:600430]. A syndrome resembling the physical anomalies found in Albright hereditary osteodystrophy. Common features are mild facial dysmorphism, congenital heart defects, distinct brachydactyly type E, mental retardation, developmental delay, seizures, autism spectrum disorder, and stocky build. Soft tissue ossification is absent, and there are no abnormalities in parathyroid hormone or calcium metabolism.[1] Function[HDAC4_HUMAN] Responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events. Histone deacetylases act via the formation of large multiprotein complexes. Involved in muscle maturation via its interaction with the myocyte enhancer factors such as MEF2A, MEF2C and MEF2D.[2] Publication Abstract from PubMedModification of chromatin and related transcription factors by histone deacetylases (HDACs) is one of the major strategies for controlling gene expression in eukaryotes. The HDAC domains of class IIa HDACs repress the respective target genes by interacting with the C-terminal region of the silencing mediator for retinoid and thyroid receptor (SMRT) repression domain 3 (SRD3c). However, latent catalytic activity suggests that their roles as deacetylases in gene regulation are unclear. Here, we found that two conserved GSI-containing motifs of SRD3c are critical for HDAC4 binding. Two SMRT peptides including these motifs commonly form a beta-hairpin structure in the cleft and block the catalytic entry site of HDAC4. They interact mainly with class IIa HDAC-specific residues of HDAC4 in a closed conformation. Structure-guided mutagenesis confirmed critical interactions between the SMRT peptides and HDAC4 and -5 as well as the contribution of the Arg1369 residue in the first motif for optimal binding to the two HDACs. These results indicate that SMRT binding does not activate the cryptic deacetylase activity of HDAC4 and explain how class IIa HDACs and the SMRT-HDAC3 complex are coordinated during gene regulation. Structural basis of the specific interaction of SMRT corepressor with histone deacetylase 4.,Park SY, Kim GS, Hwang HJ, Nam TH, Park HS, Song J, Jang TH, Lee YC, Kim JS Nucleic Acids Res. 2018 Oct 13. pii: 5128926. doi: 10.1093/nar/gky926. PMID:30321390[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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