Database Accession: DI1010008
Name: MAD1-Sin3B Interaction
PDB ID: 1e91
Experimental method: NMR
Source organism: Homo sapiens / Mus musculus
Proof of disorder:
Kd: 1.40×10-06 M
Primary publication of the structure:
Spronk CA, Tessari M, Kaan AM, Jansen JF, Vermeulen M, Stunnenberg HG, Vuister GW
The Mad1-Sin3B interaction involves a novel helical fold.
(2000) Nat. Struct. Biol. 7: 1100-4
Sin3A or Sin3B are components of a corepressor complex that mediates repression by transcription factors such as the helix-loop-helix proteins Mad and Mxi. Members of the Mad/Mxi family of repressors play important roles in the transition between proliferation and differentiation by down-regulating the expression of genes that are activated by the proto-oncogene product Myc. Here, we report the solution structure of the second paired amphipathic helix (PAH) domain (PAH2) of Sin3B in complex with a peptide comprising the N-terminal region of Mad1. This complex exhibits a novel interaction fold for which we propose the name 'wedged helical bundle'. Four alpha-helices of PAH2 form a hydrophobic cleft that accommodates an amphipathic Mad1 alpha-helix. Our data further show that, upon binding Mad1, secondary structure elements of PAH2 are stabilized. The PAH2-Mad1 structure provides the basis for determining the principles of protein interaction and selectivity involving PAH domains.
transcription corepressor activity Interacting selectively and non-covalently with a repressing transcription factor and also with the basal transcription machinery in order to stop, prevent, or reduce the frequency, rate or extent of transcription. Cofactors generally do not bind the template nucleic acid, but rather mediate protein-protein interactions between repressive transcription factors and the basal transcription machinery.
negative regulation of transcription from RNA polymerase II promoter Any process that stops, prevents, or reduces the frequency, rate or extent of transcription from an RNA polymerase II promoter.
transcription, DNA-templated The cellular synthesis of RNA on a template of DNA.
multicellular organism development The biological process whose specific outcome is the progression of a multicellular organism over time from an initial condition (e.g. a zygote or a young adult) to a later condition (e.g. a multicellular animal or an aged adult).
Entry contents: 2 distinct polypeptide molecules
Chains: B, A
Notes: No modifications of the original PDB file.
Name: Max dimerization protein 1
Source organism: Homo sapiens
Length: 13 residues
Sequence:Sequence according to PDB SEQRESNIQMLLEAADYLE
UniProtKB AC: Q05195 (positions: 8-20)Coverage: 5.9%
UniRef90 AC: UniRef90_Q05195 (positions: 8-20)
Name: Paired amphipathic helix protein Sin3b
Source organism: Mus musculus
Length: 85 residues
Sequence:Sequence according to PDB SEQRESESDSVEFNNAISYVNKIKTRFLDHPEIYRSFLEILHTYQKEQLHTKGRPFRGMSEEEVFTEVANLFRGQEDLLSEFGQFLPEAKR
UniProtKB AC: Q62141 (positions: 148-232)Coverage: 7.7%
UniRef90 AC: UniRef90_Q62141 (positions: 148-232)
The 8-20 region described in IDEAL entry IID00165 covers 100% of the sequence present in the structure. The protein region involved in the interaction contains a known functional linear motif (LIG_Sin3_1).
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