2KB6

Solution structure of onconase C87A/C104A


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 1.1 of the entry. See complete history

Literature

Impact of the C-terminal disulfide bond on the folding and stability of onconase.

Schulenburg, C.Weininger, U.Neumann, P.Meiselbach, H.Stubbs, M.T.Sticht, H.Balbach, J.Ulbrich-Hofmann, R.Arnold, U.

(2010) Chembiochem 11: 978-986

  • DOI: 10.1002/cbic.200900773
  • Primary Citation of Related Structures:  3FD7

  • PubMed Abstract: 
  • The two homologous proteins ribonuclease A and onconase fold through conserved initial contacts but differ significantly in their thermodynamic stability. A disulfide bond is located in the folding initiation site of onconase (the C-terminal part of ...

    The two homologous proteins ribonuclease A and onconase fold through conserved initial contacts but differ significantly in their thermodynamic stability. A disulfide bond is located in the folding initiation site of onconase (the C-terminal part of the protein molecule) that is missing in ribonuclease A, whereas the other three disulfide bonds of onconase are conserved in ribonuclease A. Consequently, the deletion of this C-terminal disulfide bond (C87-C104) allows the impact of the contacts in this region on the folding of onconase to be studied. We found the C87A/C104A-onconase variant to be less active and less stable than the wild-type protein, whereas the tertiary structure, which was determined by both X-ray crystallography and NMR spectroscopy, was only marginally affected. The folding kinetics of the variant, however, were found to be changed considerably in comparison to wild-type onconase. Proton exchange experiments in combination with two-dimensional NMR spectroscopy revealed differences in the native-state dynamics of the two proteins in the folding initiation site, which are held responsible for the changed folding mechanism. Likewise, the molecular dynamics simulation of the unfolding reaction indicated disparities for both proteins. Our results show that the high stability of onconase is based on the efficient stabilization of the folding initiation site by the C-terminal disulfide bond. The formation of the on-pathway intermediate, which is detectable during the folding of the wild-type protein and promotes the fast and efficient refolding reaction, requires the presence of this covalent bond.


    Organizational Affiliation

    Institute of Biochemistry and Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120 Halle, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein P-30
A
104Lithobates pipiensEC: 3.1.27.-
Find proteins for P22069 (Lithobates pipiens)
Go to UniProtKB:  P22069
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
A
L-PEPTIDE LINKINGC5 H7 N O3GLU
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2KB6 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-11-24
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance