1U7F image
Entry Detail
PDB ID:
1U7F
Keywords:
SIGNALING PROTEIN
Title:
Crystal Structure of the phosphorylated Smad3/Smad4 heterotrimeric complex
Biological Source:
Source Organism:
Homo sapiens
Host Organism:
Escherichia coli
PDB Version:
Deposition Date:
2004-08-03
Release Date:
2004-09-28
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
2.60 Å
R-Value Free:
0.24
R-Value Work:
0.23
Space Group:
P 21 21 21
1U7F validation report
Macromolecular Entities
Protein Blast
Polymer Type:polypeptide(L)
Description:Mothers against decapentaplegic homolog 3
Chain IDs:A, C
Chain Length:198
Number of Molecules:2
Biological Source:Homo sapiens
UniProt ID:P84022 Pfam ID:PF03166
Protein Blast
Polymer Type:polypeptide(L)
Description:Mothers against decapentaplegic homolog 4
Chain IDs:B
Chain Length:239
Number of Molecules:1
Biological Source:Homo sapiens
UniProt ID:Q13485 Pfam ID:PF03166
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
SEP A SER PHOSPHOSERINE
Primary Citation
Structural basis of heteromeric smad protein assembly in tgf-Beta signaling
Mol.Cell 15 813 823 (2004)
PMID: 15350224 DOI: 10.1016/j.molcel.2004.07.016

Abstact

The formation of protein complexes between phosphorylated R-Smads and Smad4 is a central event in the TGF-beta signaling pathway. We have determined the crystal structure of two R-Smad/Smad4 complexes, Smad3/Smad4 to 2.5 angstroms, and Smad2/Smad4 to 2.7 angstroms. Both complexes are heterotrimers, comprising two phosphorylated R-Smad subunits and one Smad4 subunit, a finding that was corroborated by isothermal titration calorimetry and mutational studies. Preferential formation of the R-Smad/Smad4 heterotrimer over the R-Smad homotrimer is largely enthalpy driven, contributed by the unique presence of strong electrostatic interactions within the heterotrimeric interfaces. The study supports a common mechanism of Smad protein assembly in TGF-beta superfamily signaling.

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Disease

Primary Citation of related structures
1U7V