1NVO

Solution structure of a four-helix bundle model, apo-DF1


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 40 
  • Conformers Submitted: 14 
  • Selection Criteria: structures with acceptable covalent geometry,structures with favorable non-bond energy,structures with the least restraint violations,structures with the lowest energy 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Preorganization of molecular binding sites in designed diiron proteins

Maglio, O.Nastri, F.Pavone, V.Lombardi, A.DeGrado, W.F.

(2003) Proc Natl Acad Sci U S A 100: 3772-3777

  • DOI: https://doi.org/10.1073/pnas.0730771100
  • Primary Citation of Related Structures:  
    1NVO

  • PubMed Abstract: 

    De novo protein design provides an attractive approach to critically test the features that are required for metalloprotein structure and function. Previously we designed and crystallographically characterized an idealized dimeric model for the four-helix bundle class of diiron and dimanganese proteins [Dueferri 1 (DF1)]. Although the protein bound metal ions in the expected manner, access to its active site was blocked by large bulky hydrophobic residues. Subsequently, a substrate-access channel was introduced proximal to the metal-binding center, resulting in a protein with properties more closely resembling those of natural enzymes. Here we delineate the energetic and structural consequences associated with the introduction of these binding sites. To determine the extent to which the binding site was preorganized in the absence of metal ions, the apo structure of DF1 in solution was solved by NMR and compared with the crystal structure of the di-Zn(II) derivative. The overall fold of the apo protein was highly similar to that of the di-Zn(II) derivative, although there was a rotation of one of the helices. We also examined the thermodynamic consequences associated with building a small molecule-binding site within the protein. The protein exists in an equilibrium between folded dimers and unfolded monomers. DF1 is a highly stable protein (K(diss) = 0.001 fM), but the dissociation constant increases to 0.6 nM (deltadeltaG = 5.4 kcalmol monomer) as the active-site cavity is increased to accommodate small molecules.


  • Organizational Affiliation

    Department of Chemistry, University of Napoli Federico II, Complesso Universitario Monte S. Angelo, I-80126 Napoli, Italy.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Homodimeric Alpha2 Four-Helix Bundle
A, B
50N/AMutation(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: 40 
  • Conformers Submitted: 14 
  • Selection Criteria: structures with acceptable covalent geometry,structures with favorable non-bond energy,structures with the least restraint violations,structures with the lowest energy 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-03-25
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-02-23
    Changes: Data collection, Database references, Derived calculations
  • Version 1.4: 2024-11-06
    Changes: Data collection, Structure summary