Macromolecule Content

• Total Structure Weight: 11.49 kDa 
• Atom Count: 806 
• Residue Count: 104 
• Unique protein chains: 1

2KNV

NMR dimer structure of the UBA domain of p62 (SQSTM1)

• DOI: 10.2210/pdb2KNV/pdb

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


• Deposited: 2009-09-04 Released: 2009-12-15 
• Deposition Author(s): Long, J.E., Searle, M.S.

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Experimental Data Snapshot

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

Literature

Dimerisation of the UBA Domain of p62 Inhibits Ubiquitin Binding and Regulates NF-kappaB Signalling

Long, J., Garner, T.P., Pandya, M.J., Craven, C.J., Chen, P., Shaw, B., Williamson, M.P., Layfield, R., Searle, M.S.

(2009) J Mol Biol 

• PubMed: 19931284 
• DOI: 10.1016/j.jmb.2009.11.032
• Primary Citation of Related Structures:  
  2KNV


• PubMed Abstract: 
  

The ubiquitin (Ub)-binding p62 scaffold protein (encoded by the SQSTM1 gene) regulates a diverse range of signalling pathways leading to activation of the nuclear factor kappa B (NF-kappaB) family of transcription factors and is an important regulator of macroautophagy. Mutations within the gene encoding p62 are commonly found in patients with Paget's disease of bone and largely cluster within the C-terminal ubiquitin-associated (UBA) domain, impairing its ability to bind Ub, resulting in dysregulated NF-kappaB signalling. However, precisely how Ub-binding is regulated at the molecular level is unclear. NMR relaxation dispersion experiments, coupled with concentration-dependent NMR, CD, isothermal titration calorimetry and fluorescence kinetic measurements, reveal that the p62 UBA domain forms a highly stable dimer (K(dim) approximately 4-12 microM at 298 K). NMR analysis shows that the dimer interface partially occludes the Ub-binding surface, particularly at the C-terminus of helix 3, making UBA dimerisation and Ub-binding mutually exclusive processes. Somewhat unusually, the monomeric UBA appears to be the biologically active form and the dimer appears to be the inactive one. Engineered point mutations in loop 1 (E409K and G410K) are shown to destabilise the dimer interface, lead to a higher proportion of the bound monomer and, in NF-kappaB luciferase reporter assays, are associated with reduced NF-kappaB activity compared with wt-p62.

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Organizational Affiliation: 

Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RD, UK.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Sequestosome-1	A, B	52	Homo sapiens	Mutation(s): 0  Gene Names: SQSTM1, ORCA, OSIL
Find proteins for Q13501 (Homo sapiens) Explore Q13501  Go to UniProtKB:  Q13501
NIH Common Fund Data Resources
PHAROS:  Q13501 GTEx:  ENSG00000161011

Experimental Data & Validation

Experimental Data

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

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-09-04 
• Released Date: 2009-12-15 
Deposition Author(s): Long, J.E., Searle, M.S.

Revision History 

• Version 1.0: 2009-12-15
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance