2A37

Solution structure of the T22G mutant of N-terminal SH3 domain of DRK (DRKN SH3 DOMAIN)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Comparison of the Unstable drkN SH3 Domain and a Stable Mutant

Bezsonova, I.Singer, A.Choy, W.-Y.Tollinger, M.Forman-Kay, J.D.

(2005) Biochemistry 44: 15550-15560

  • DOI: 10.1021/bi0512795
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The N-terminal SH3 domain of the Drosophila adapter protein Drk (drkN SH3 domain) is marginally stable (DeltaG(U) = 1 kcal/mol) and exists in equilibrium between folded and highly populated unfolded states. The single substitution T22G, however, comp ...

    The N-terminal SH3 domain of the Drosophila adapter protein Drk (drkN SH3 domain) is marginally stable (DeltaG(U) = 1 kcal/mol) and exists in equilibrium between folded and highly populated unfolded states. The single substitution T22G, however, completely stabilizes the protein (DeltaG(U) = 4.0 kcal/mol). To probe the causes of instability of the wild-type (WT) protein and the dramatic stabilization of the mutant, we determined and compared nuclear magnetic resonance structures of the folded WT and mutant drkN SH3 domains. Residual dipolar coupling (RDC) and carbonyl chemical-shift anisotropy (C'-CSA) restraints measured for the WT and T22G domains were used for calculating the structures. The structures for the WT and mutant are highly similar. Thr22 of the WT and Gly22 of the mutant are at the i + 2 position of the diverging, type-II beta-turn. Interestingly, not only Gly22 but also Thr22 successfully adopt an alpha(L) conformation, required at this position of the turn, despite the fact that positive phi values are energetically unfavorable and normally disallowed for threonine residues. Forcing the Thr22 residue into this unnatural conformation increases the free energy of the folded state of the WT domain relative to its T22G mutant. Evidence for residual helix formation in the diverging turn region has been previously reported for the unfolded state of the WT drkN SH3 domain, and this, in addition to other residual structure, has been proposed to play a role in decreasing the free energy of the unfolded state of the protein. Together these data provide evidence that both increasing the free energy of the folded state and decreasing the free energy of the unfolded state of the protein contribute to instability of the WT drkN SH3 domain.


    Organizational Affiliation

    The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein E(sev)2B
A
59Drosophila melanogasterMutation(s): 1 
Gene Names: drk (E(sev)2B)
Find proteins for Q08012 (Drosophila melanogaster)
Go to UniProtKB:  Q08012
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2A37 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-12-13
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance