224L

THE ENERGETIC COST AND THE STRUCTURAL CONSEQUENCES OF BURYING A HYDROXYL GROUP WITHIN THE CORE OF A PROTEIN DETERMINED FROM ALA TO SER AND VAL TO THR SUBSTITUTIONS IN T4 LYSOZYME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Observed: 0.164 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Energetic cost and structural consequences of burying a hydroxyl group within the core of a protein determined from Ala-->Ser and Val-->Thr substitutions in T4 lysozyme.

Blaber, M.Lindstrom, J.D.Gassner, N.Xu, J.Heinz, D.W.Matthews, B.W.

(1993) Biochemistry 32: 11363-11373

  • DOI: 10.1021/bi00093a013
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • In order to determine the thermodynamic cost of introducing a polar group within the core of a protein, a series of nine Ala-->Ser and 3 Val-->Thr substitutions was constructed in T4 lysozyme. The sites were all within alpha-helices but ranged from f ...

    In order to determine the thermodynamic cost of introducing a polar group within the core of a protein, a series of nine Ala-->Ser and 3 Val-->Thr substitutions was constructed in T4 lysozyme. The sites were all within alpha-helices but ranged from fully solvent-exposed to totally buried. The range of destabilization incurred by the Ala-->Ser substitutions was found to be very similar to that for the Val-->Thr replacements. For the solvent-exposed and partly exposed sites the destabilization was modest (approximately less than 0.5 kcal/mol). For the completely buried sites the destabilization was larger, but variable (approximately 1-3 kcal/mol). Crystal structure determinations showed that the Ala-->Ser mutant structures were, in general, very similar to their wild-type counterparts, even though the replacements introduce a hydroxyl group. This is in part because the introduced serines are all within alpha-helices and at congested sites can avoid steric clashes with surrounding atoms by making a hydrogen bond to a backbone carbonyl oxygen in the preceding turn of the helix. The three substituted threonine side chains essentially superimpose on their valine counterparts but display somewhat larger conformational adjustments. The results illustrate how a protein structure will adapt in different ways to avoid the presence of an unsatisfied hydrogen bond donor or acceptor. In the most extreme case, Val 149-->Thr, which is also the most destabilizing variant (delta delta G = 2.8 kcal/mol), a water molecule is incorporated in the mutant structure in order to provide a hydrogen-bonding partner. The results are consistent with the view that many hydrogen bonds within proteins contribute only marginally to stability but that noncharged polar groups that lack a hydrogen-bonding partner are very destabilizing (delta delta G approximately greater than 3 kcal/mol). Supportive of other studies, the alpha-helix propensity of alanine is seen to be higher than that of serine (delta delta G = 0.46 +/- 0.04 kcal/mol), while threonine and valine are similar in alpha-helix propensity.


    Related Citations: 
    • Control of Enzyme Activity by an Engineered Disulfide Bond
      Matsumura, M., Matthews, B.W.
      (1989) Science 243: 792
    • Structure of Bacteriophage T4 Lysozyme Refined at 1.7 Angstroms Resolution
      Weaver, L.H., Matthews, B.W.
      (1987) J Mol Biol 193: 189

    Organizational Affiliation

    Institute of Molecular Biology, Howard Hughes Medical Institute, Eugene, Oregon.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
T4 LYSOZYME
A
164Escherichia virus T4Mutation(s): 0 
Gene Names: E
EC: 3.2.1.17
Find proteins for P00720 (Enterobacteria phage T4)
Go to UniProtKB:  P00720
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BME
Query on BME

Download CCD File 
A
BETA-MERCAPTOETHANOL
C2 H6 O S
DGVVWUTYPXICAM-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Observed: 0.164 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.1α = 90
b = 61.1β = 90
c = 97γ = 120
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other