6XXZ

Crystal structure of a de novo designed parallel four-helix coiled coil, 2-EK-4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.184 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

RobustDe Novo-Designed Homotetrameric Coiled Coils.

Edgell, C.L.Savery, N.J.Woolfson, D.N.

(2020) Biochemistry 59: 1087-1092

  • DOI: https://doi.org/10.1021/acs.biochem.0c00082
  • Primary Citation of Related Structures:  
    6XXZ, 6XY0, 6XY1

  • PubMed Abstract: 

    De novo -designed protein domains are increasingly being applied in biotechnology, cell biology, and synthetic biology. Therefore, it is imperative that these proteins be robust to superficial changes; i.e., small changes to their amino acid sequences should not cause gross structural changes. In turn, this allows properties such as stability and solubility to be tuned without affecting structural attributes like tertiary fold and quaternary interactions. Reliably designed proteins with predictable behaviors may then be used as scaffolds to incorporate function, e.g., through the introduction of features for small-molecule, metal, or macromolecular binding, and enzyme-like active sites. Generally, achieving this requires the starting protein fold to be well understood. Herein, we focus on designing α-helical coiled coils, which are well studied, widespread, and often direct protein-protein interactions in natural systems. Our initial investigations reveal that a previously designed parallel, homotetrameric coiled coil, CC-Tet, is not robust to sequence changes that were anticipated to maintain its structure. Instead, the alterations switch the oligomeric state from tetramer to trimer. To improve the robustness of designed homotetramers, additional sequences based on CC-Tet were produced and characterized in solution and by X-ray crystallography. Of these updated sequences, one is robust to truncation and to changes in surface electrostatics; we call this CC-Tet*. Variants of the general CC-Tet* design provide a set of homotetrameric coiled coils with unfolding temperatures in the range from 40 to >95 °C. We anticipate that these will be of use in applications requiring robust and well-defined tetramerization domains.


  • Organizational Affiliation

    School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
2-EK-4
A, B
32synthetic constructMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.184 
  • Space Group: C 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.56α = 90
b = 50.84β = 90
c = 43.94γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
iMOSFLMdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Biotechnology and Biological Sciences Research Council (BBSRC)United KingdomBB/S002820/1
Biotechnology and Biological Sciences Research Council (BBSRC)United KingdomEP/L016494/1
Engineering and Physical Sciences Research CouncilUnited KingdomEP/L016494/1

Revision History  (Full details and data files)

  • Version 1.0: 2020-03-18
    Type: Initial release
  • Version 1.1: 2020-03-25
    Changes: Database references