2JOF

The Trp-cage: Optimizing the Stability of a Globular Miniprotein


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 28 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

The Trp-cage: optimizing the stability of a globular miniprotein

Barua, B.Lin, J.C.Williams, V.D.Kummler, P.Neidigh, J.W.Andersen, N.H.

(2008) Protein Eng Des Sel 21: 171-185

  • DOI: https://doi.org/10.1093/protein/gzm082
  • Primary Citation of Related Structures:  
    2JOF

  • PubMed Abstract: 

    The Trp-cage, as the smallest miniprotein, remains the subject of numerous computational and experimental studies of protein folding dynamics and pathways. The original Trp-cage (NLYIQWLKDGGPSSGRPPPS, Tm = 42 degrees C) can be significantly stabilized by mutations; melting points as high as 64 degrees C are reported. In helical portions of the structure, each allowed replacement of Leu, Ile, Lys or Ser residues by Ala results in a 1.5 (+/-0.35) kJ/mol fold stabilization. No changes in structure or fluxionality of the core results upon stabilization. Contrary to the initial hypothesis, specific Pro/Trp interactions are not essential for core formation. The entropic advantage of Pro versus Ala (DeltaDeltaS(U) = 11 +/- 2 J/mol K) was measured at the solvent-exposed P17 site. Pro-Ala mutations at two of the three prolines (P12 and P18) that encage the indole ring result in less fold destabilization (2.3-3.4 kJ/mol). However, a P19A mutation reduces fold stability by 16 kJ/mol reflecting a favorable Y3/P19 interaction as well as Trp burial. The Y3/P19 hydrophobic staple interaction defines the folding motif as an 18-residue unit. Other stabilizing features that have been identified include a solvent-exposed Arg/Asp salt bridge (3.4-6 kJ/mol) and a buried H-bonded Ser side chain ( approximately 10 kJ/mol).


  • Organizational Affiliation

    Department of Chemistry, University of Washington, Seattle, WA 98195, USA.


Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TRP-CAGE20synthetic constructMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 28 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-03-04
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2020-02-05
    Changes: Data collection, Database references, Derived calculations, Experimental preparation, Other, Source and taxonomy
  • Version 1.3: 2023-06-14
    Changes: Database references, Other
  • Version 1.4: 2023-12-20
    Changes: Data collection, Other