Biological Assembly 1  

 3D View: Structure

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 12.30 kDa 
• Atom Count: 869 
• Modelled Residue Count: 110 
• Deposited Residue Count: 110 
• Unique protein chains: 2

2KXQ

Solution Structure of Smurf2 WW2 and WW3 bound to Smad7 PY motif containing peptide

• DOI: 10.2210/pdb2KXQ/pdb
• BMRB: 16923

• Classification: PROTEIN BINDING
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2010-05-11 Released: 2010-10-13 
• Deposition Author(s): Chong, A., Lin, H., Wrana, J., Forman-Kay, J.D.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 200 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 

Literature

Coupling of tandem Smad ubiquitination regulatory factor (Smurf) WW domains modulates target specificity.

Chong, P.A., Lin, H., Wrana, J.L., Forman-Kay, J.D.

(2010) Proc Natl Acad Sci U S A 107: 18404-18409

• PubMed: 20937913 
• DOI: 10.1073/pnas.1003023107
• Primary Citation of Related Structures:  
  2KXQ


• PubMed Abstract: 
  

Smad ubiquitination regulatory factor 2 (Smurf2) is an E3 ubiquitin ligase that participates in degradation of TGF-β receptors and other targets. Smurf2 WW domains recognize PPXY (PY) motifs on ubiquitin ligase target proteins or on adapters, such as Smad7, that bind to E3 target proteins. We previously demonstrated that the isolated WW3 domain of Smurf2, but not the WW2 domain, can directly bind to a Smad7 PY motif. We show here that the WW2 augments this interaction by binding to the WW3 and making auxiliary contacts with the PY motif and a novel E/D-S/T-P motif, which is N-terminal to all Smad PY motifs. The WW2 likely enhances the selectivity of Smurf2 for the Smad proteins. NMR titrations confirm that Smad1 and Smad2 are bound by Smurf2 with the same coupled WW domain arrangement used to bind Smad7. The analogous WW domains in the short isoform of Smurf1 recognize the Smad7 PY peptide using the same coupled mechanism. However, a longer Smurf1 isoform, which has an additional 26 residues in the inter-WW domain linker, is only partially able to use the coupled WW domain binding mechanism. The longer linker results in a decrease in affinity for the Smad7 peptide. Interdomain coupling of WW domains enhances selectivity and enables the tuning of interactions by isoform switching.

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Organizational Affiliation: 

Program in Molecular Structure and Function, Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
E3 ubiquitin-protein ligase SMURF2	A	90	Homo sapiens	Mutation(s): 0  Gene Names: SMURF2 EC: 2.3.2.26
Find proteins for Q9HAU4 (Homo sapiens) Explore Q9HAU4  Go to UniProtKB:  Q9HAU4
NIH Common Fund Data Resources
PHAROS:  Q9HAU4 GTEx:  ENSG00000108854

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Smad7 PY motif containing peptide	B	20	Homo sapiens	Mutation(s): 0  Gene Names: SMAD7, MADH7, MADH8
Find proteins for O15105 (Homo sapiens) Explore O15105  Go to UniProtKB:  O15105
NIH Common Fund Data Resources
PHAROS:  O15105 GTEx:  ENSG00000101665

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 200 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 2KXQ Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2010-05-11 
• Released Date: 2010-10-13 
Deposition Author(s): Chong, A., Lin, H., Wrana, J., Forman-Kay, J.D.

Revision History  

• Version 1.0: 2010-10-13
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance
• Version 1.2: 2012-06-20
  Changes: Database references