1JTN

Alternative Structures of a Sequence Extended T4 Lysozyme Show that the Highly Conserved Beta-Sheet Region has weak intrinsic Folding Propensity


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.314 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.232 

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This is version 1.3 of the entry. See complete history


Literature

Crystal Structures of a T4-lysozyme Duplication-extension Mutant Demonstrate that the Highly Conserved beta-Sheet Region has Low Intrinsic Folding Propensity

Sagermann, M.Matthews, B.W.

(2002) J Mol Biol 316: 931-940

  • DOI: 10.1006/jmbi.2001.5376
  • Primary Citation of Related Structures:  
    1JTM, 1JTN

  • PubMed Abstract: 
  • Residues 24 to 35 of T4 lysozyme correspond to the second and third strands of a region of beta-sheet that is highly conserved in all known lysozyme and chitinase structures. To evaluate the intrinsic propensity of these amino acid residues to form a defined structure they were added at the C terminus of the native protein, together with a dipeptide linker ...

    Residues 24 to 35 of T4 lysozyme correspond to the second and third strands of a region of beta-sheet that is highly conserved in all known lysozyme and chitinase structures. To evaluate the intrinsic propensity of these amino acid residues to form a defined structure they were added at the C terminus of the native protein, together with a dipeptide linker. Two crystal structures of this active, mutant protein were obtained, to 1.9A and 2.3A resolution, respectively. Even though the crystal conditions are similar, the appended sequence adopts very different secondary structures. In one case it is weakly structured and appears to extend through the active-site cleft, perhaps in part adding an extra strand to the original beta-sheet. In the other crystal form the extension is largely alpha-helical. The formation of these alternative structures shows that the sequence does not have a strong intrinsic propensity to form a unique fold (either beta-sheet or otherwise). The results also suggest that structural conservation during evolution does not necessarily depend on sequence conservation or the conservation of folding propensity.


    Related Citations: 
    • Structural Characterization of an Engineered Tandem Repeat contrasts the Importance of Context and Sequence in Protein Folding
      Sagermann, M., Baase, W.A., Matthews, B.W.
      (1999) Proc Natl Acad Sci U S A 96: 6078
    • Structure of Bacteriophage T4 Lysozyme Refined at 1.7 A Resolution
      Weaver, L.H., Matthews, B.W.
      (1987) J Mol Biol 193: 189

    Organizational Affiliation

    Institute of Molecular Biology, Howard Hughes Medical Institute and Department of Physics, 1229 University of Oregon, Eugene, OR 97403-1229, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
LYSOZYMEA, B178Escherichia virus T4Mutation(s): 2 
Gene Names: E
EC: 3.2.1.17
UniProt
Find proteins for P00720 (Enterobacteria phage T4)
Explore P00720 
Go to UniProtKB:  P00720
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00720
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.314 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.232 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.125α = 90
b = 32.314β = 102.64
c = 85.925γ = 90
Software Package:
Software NamePurpose
AMoREphasing
TNTrefinement
MOSFLMdata reduction
CCP4data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-03-20
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations