Macromolecule Content

• Total Structure Weight: 12.31 kDa 
• Atom Count: 869 
• Modelled Residue Count: 105 
• Deposited Residue Count: 105 
• Unique protein chains: 2

1S5Q

Solution Structure of Mad1 SID-mSin3A PAH2 Complex

• DOI: 10.2210/pdb1S5Q/pdb
• BMRB: 4635

• Classification: TRANSCRIPTION
• Organism(s): Mus musculus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2004-01-21 Released: 2004-07-06 
• Deposition Author(s): Swanson, K.A., Knoepfler, P.S., Huang, K., Kang, R.S., Cowley, S.M., Laherty, C.D., Eisenman, R.N., Radhakrishnan, I.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 80 
• Conformers Submitted: 20 
• Selection Criteria: The submitted conformers are the 20 structures with the lowest restraint energies, restraint violations, and RMS deviations from ideal covalent geometry 

Literature

HBP1 and Mad1 repressors bind the Sin3 corepressor PAH2 domain with opposite helical orientations.

Swanson, K.A., Knoepfler, P.S., Huang, K., Kang, R.S., Cowley, S.M., Laherty, C.D., Eisenman, R.N., Radhakrishnan, I.

(2004) Nat Struct Mol Biol 11: 738-746

• PubMed: 15235594 
• DOI: 10.1038/nsmb798
• Primary Citation of Related Structures:  
  1S5R, 1S5Q


• PubMed Abstract: 
  

Recruitment of the histone deacetylase (HDAC)-associated Sin3 corepressor is an obligatory step in many eukaryotic gene silencing pathways. Here we show that HBP1, a cell cycle inhibitor and regulator of differentiation, represses transcription in a HDAC/Sin3-dependent manner by targeting the mammalian Sin3A (mSin3A) PAH2 domain. HBP1 is unrelated to the Mad1 repressor for which high-resolution structures in complex with PAH2 have been described. We show that like Mad1, the HBP1 transrepression domain binds through a helical structure to the hydrophobic cleft of mSin3A PAH2. Notably, the HBP1 helix binds PAH2 in a reversed orientation relative to Mad1 and, equally unexpectedly, this is correlated with a chain reversal of the minimal Sin3 interaction motifs. These results not only provide insights into how multiple, unrelated transcription factors recruit the same coregulator, but also have implications for how sequence similarity searches are conducted.

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Related Citations: 

• Solution Structure of the Interacting Domains of the Mad-Sin3 Complex: Implications for Recruitment of a Chromatin-Modifying Complex
  Brubaker, K., Cowley, S.M., Huang, K., Loo, L., Yochum, G.S., Ayer, D.E., Eisenman, R.N., Radhakrishnan, I.
  (2000) Cell 103: 655

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Organizational Affiliation: 

Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
MAD protein	A	16	N/A	Mutation(s): 0
Find proteins for Q05195 (Homo sapiens) Explore Q05195  Go to UniProtKB:  Q05195
NIH Common Fund Data Resources
PHAROS:  Q05195 GTEx:  ENSG00000059728

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Sin3a protein	B	89	Mus musculus	Mutation(s): 0  Gene Names: Sin3a, Kiaa4126
Find proteins for Q60520 (Mus musculus) Explore Q60520  Go to UniProtKB:  Q60520

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 80 
• Conformers Submitted: 20 
• Selection Criteria: The submitted conformers are the 20 structures with the lowest restraint energies, restraint violations, and RMS deviations from ideal covalent geometry 
• OLDERADO: 1S5Q Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2004-01-21 
• Released Date: 2004-07-06 
Deposition Author(s): Swanson, K.A., Knoepfler, P.S., Huang, K., Kang, R.S., Cowley, S.M., Laherty, C.D., Eisenman, R.N., Radhakrishnan, I.

Revision History  

• Version 1.0: 2004-07-06
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance