1L23

ENHANCED PROTEIN THERMOSTABILITY FROM SITE-DIRECTED MUTATIONS THAT DECREASE THE ENTROPY OF UNFOLDING


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.157 

wwPDB Validation   3D Report Full Report


This is version 2.1 of the entry. See complete history


Literature

Enhanced protein thermostability from site-directed mutations that decrease the entropy of unfolding.

Matthews, B.W.Nicholson, H.Becktel, W.J.

(1987) Proc Natl Acad Sci U S A 84: 6663-6667

  • DOI: https://doi.org/10.1073/pnas.84.19.6663
  • Primary Citation of Related Structures:  
    1L23, 1L24

  • PubMed Abstract: 

    It is proposed that the stability of a protein can be increased by selected amino acid substitutions that decrease the configurational entropy of unfolding. Two such substitutions, one of the form Xaa----Pro and the other of the form Gly----Xaa, were constructed in bacteriophage T4 lysozyme at sites consistent with the known three-dimensional structure. Both substitutions stabilize the protein toward reversible and irreversible thermal denaturation at physiological pH. The substitutions have no effect on enzymatic activity. High-resolution crystallographic analysis of the proline-containing mutant protein (Ala-82----Pro) shows that its three-dimensional structure is essentially identical with the wild-type enzyme. The overall structure of the other mutant enzyme (Gly-77----Ala) is also very similar to wild-type lysozyme, although there are localized conformational adjustments in the vicinity of the altered amino acid. The combination of a number of such amino acid replacements, each of which is expected to contribute approximately 1 kcal/mol (1 cal = 4.184 J) to the free energy of folding, may provide a general strategy for substantial improvement in the stability of a protein.


  • Organizational Affiliation

    Institute of Molecular Biology, University of Oregon, Eugene 97403.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
T4 LYSOZYME164Tequatrovirus T4Mutation(s): 1 
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
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.157 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.2α = 90
b = 61.2β = 90
c = 97.2γ = 120
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1990-01-15
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other
  • Version 2.0: 2022-11-23
    Type: Remediation
    Changes: Advisory, Atomic model, Data collection, Database references, Other, Source and taxonomy
  • Version 2.1: 2024-05-22
    Changes: Data collection