2o94 | pdb_00002o94
The 97H/F mutant Structure of a glutamine-rich domain from histone deacetylase 4
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] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedGlutamine-rich sequences exist in a wide range of proteins across multiple species. A subset of glutamine-rich sequences has been shown to form amyloid fibers implicated in human diseases. The physiological functions of these sequence motifs are not well understood, partly because of the lack of structural information. Here we have determined a high-resolution structure of a glutamine-rich domain from human histone deacetylase 4 (HDAC4) by x-ray crystallography. The glutamine-rich domain of HDAC4 (19 glutamines of 68 residues) folds into a straight alpha-helix that assembles as a tetramer. In contrast to most coiled coil proteins, the HDAC4 tetramer lacks regularly arranged apolar residues and an extended hydrophobic core. Instead, the protein interfaces consist of multiple hydrophobic patches interspersed with polar interaction networks, wherein clusters of glutamines engage in extensive intra- and interhelical interactions. In solution, the HDAC4 tetramer undergoes rapid equilibrium with monomer and intermediate species. Structure-guided mutations that expand or disrupt hydrophobic patches drive the equilibrium toward the tetramer or monomer, respectively. We propose that a general role of glutamine-rich motifs be to mediate protein-protein interactions characteristic of a large component of polar interaction networks that may facilitate reversible assembly and disassembly of protein complexes. Crystal structure of a conserved N-terminal domain of histone deacetylase 4 reveals functional insights into glutamine-rich domains.,Guo L, Han A, Bates DL, Cao J, Chen L Proc Natl Acad Sci U S A. 2007 Mar 13;104(11):4297-302. Epub 2007 Mar 5. PMID:17360518[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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