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From Proteopedia
Solution structure of the NRSF/REST-mSin3B PAH1 complex
Structural highlights
Function[SIN3B_MOUSE] Acts as a transcriptional repressor. Interacts with MXI1 to repress MYC responsive genes and antagonize MYC oncogenic activities. Interacts with MAD-MAX heterodimers by binding to MAD. The heterodimer then represses transcription by tethering SIN3B to DNA. Also forms a complex with FOXK1 which represses transcription.[1] [2] [REST_HUMAN] Transcriptional repressor which binds neuron-restrictive silencer element (NRSE) and represses neuronal gene transcription in non-neuronal cells. Restricts the expression of neuronal genes by associating with two distinct corepressors, mSin3 and CoREST, which in turn recruit histone deacetylase to the promoters of REST-regulated genes. Mediates repression by recruiting the BHC complex at RE1/NRSE sites which acts by deacetylating and demethylating specific sites on histones, thereby acting as a chromatin modifier.[3] [4] [5] [6] 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 PubMedIn non-neuronal cells and neuronal progenitors, many neuron-specific genes are repressed by a neural restrictive silencer factor (NRSF)/repressor element 1 silencing transcription factor (REST), which is an essential transcriptional repressor recruiting the Sin3-HDAC complex. Sin3 contains four paired amphipathic helix (PAH) domains, PAH1, PAH2, PAH3 and PAH4. A specific target repressor for Sin3 is likely to bind to one of them independently. So far, only the tertiary structures of PAH2 domain complexes, when bound to the Sin3-interacting domains of Mad1 and HBP1, have been determined. Here, we reveal that the N-terminal repressor domain of NRSF/REST binds to the PAH1 domain of mSin3B, and determine the structure of the PAH1 domain associated with the NRSF/REST minimal repressor domain. Compared to the PAH2 structure, PAH1 holds a rather globular four-helix bundle structure with a semi-ordered C-terminal tail. In contrast to the amphipathic alpha-helix of Mad1 or HBP1 bound to PAH2, the short hydrophobic alpha-helix of NRSF/REST is captured in the cleft of PAH1. A nuclear hormone receptor corepressor, N-CoR has been found to bind to the PAH1 domain with a lower affinity than NRSF/REST by using its C-terminal region, which contains fewer hydrophobic amino acid residues than the NRSF/REST helix. For strong binding to a repressor, PAH1 seems to require a short alpha-helix consisting of mostly hydrophobic amino acid residues within the repressor. Each of the four PAH domains of Sin3 seems to interact with a characteristic helix of a specific repressor; PAH1 needs a mostly hydrophobic helix and PAH2 needs an amphipathic helix in each target repressor. The neural repressor NRSF/REST binds the PAH1 domain of the Sin3 corepressor by using its distinct short hydrophobic helix.,Nomura M, Uda-Tochio H, Murai K, Mori N, Nishimura Y J Mol Biol. 2005 Dec 9;354(4):903-15. Epub 2005 Oct 26. PMID:16288918[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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