233L

T4 LYSOZYME MUTANT M120L


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Work: 0.169 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Context-dependent protein stabilization by methionine-to-leucine substitution shown in T4 lysozyme.

Lipscomb, L.A.Gassner, N.C.Snow, S.D.Eldridge, A.M.Baase, W.A.Drew, D.L.Matthews, B.W.

(1998) Protein Sci 7: 765-773

  • DOI: 10.1002/pro.5560070326
  • Primary Citation of Related Structures:  
    230L, 231L, 232L, 233L, 234L

  • PubMed Abstract: 
  • The substitution of methionines with leucines within the interior of a protein is expected to increase stability both because of a more favorable solvent transfer term as well as the reduced entropic cost of holding a leucine side chain in a defined ...

    The substitution of methionines with leucines within the interior of a protein is expected to increase stability both because of a more favorable solvent transfer term as well as the reduced entropic cost of holding a leucine side chain in a defined position. Together, these two terms are expected to contribute about 1.4 kcal/mol to protein stability for each Met --> Leu substitution when fully buried. At the same time, this expected beneficial effect may be offset by steric factors due to differences in the shape of leucine and methionine. To investigate the interplay between these factors, all methionines in T4 lysozyme except at the amino-terminus were individually replaced with leucine. Of these mutants, M106L and M120L have stabilities 0.5 kcal/mol higher than wild-type T4 lysozyme, while M6L is significantly destabilized (-2.8 kcal/mol). M102L, described previously, is also destabilized (-0.9 kcal/mol). Based on this limited sample it appears that methionine-to-leucine substitutions can increase protein stability but only in a situation where the methionine side chain is fully or partially buried, yet allows the introduction of the leucine without concomitant steric interference. The variants, together with methionine-to-lysine substitutions at the same sites, follow the general pattern that substitutions at rigid, internal sites tend to be most destabilizing, whereas replacements at more solvent-exposed sites are better tolerated.


    Organizational Affiliation

    Institute of Molecular Biology, Howard Hughes Medical Institute and Department of Chemistry, University of Oregon, Eugene 97403, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
T4 LYSOZYMEA164Escherichia virus T4Mutation(s): 3 
Gene Names: T4 LYSOZYMEE
EC: 3.2.1.17
Find proteins for P00720 (Enterobacteria phage T4)
Explore P00720 
Go to UniProtKB:  P00720
Protein Feature View
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  • Reference Sequence
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: 1.90 Å
  • R-Value Work: 0.169 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.93α = 90
b = 60.93β = 90
c = 97.3γ = 120
Software Package:
Software NamePurpose
TNTrefinement
SDMSdata reduction
SDMSdata scaling
TNTphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-01-14
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance