3GUL

T4 lysozyme M102E/L99A mutant with buried charge in apolar cavity--ethylbenzene binding

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.07 Å
  • R-Value Free: 0.293 
  • R-Value Work: 0.237 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history. 

Literature

Use of stabilizing mutations to engineer a charged group within a ligand-binding hydrophobic cavity in T4 lysozyme.

Liu, L., Baase, W.A., Michael, M.M., Matthews, B.W.

(2009) Biochemistry 48: 8842-8851

  • DOI: 10.1021/bi900685j
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Both large-to-small and nonpolar-to-polar mutations in the hydrophobic core of T4 lysozyme cause significant loss in stability. By including supplementary stabilizing mutations we constructed a variant that combines the cavity-creating substitution L ...

    Both large-to-small and nonpolar-to-polar mutations in the hydrophobic core of T4 lysozyme cause significant loss in stability. By including supplementary stabilizing mutations we constructed a variant that combines the cavity-creating substitution Leu99 --> Ala with the buried charge mutant Met102 --> Glu. Crystal structure determination confirmed that this variant has a large cavity with the side chain of Glu102 located within the cavity wall. The cavity includes a large disk-shaped region plus a bulge. The disk-like region is essentially nonpolar, similar to L99A, while the Glu102 substituent is located in the vicinity of the bulge. Three ordered water molecules bind within this part of the cavity and appear to stabilize the conformation of Glu102. Glu102 has an estimated pKa of about 5.5-6.5, suggesting that it is at least partially charged in the crystal structure. The polar ligands pyridine, phenol and aniline bind within the cavity, and crystal structures of the complexes show one or two water molecules to be retained. Nonpolar ligands of appropriate shape can also bind in the cavity and in some cases exclude all three water molecules. This disrupts the hydrogen-bond network and causes the Glu102 side chain to move away from the ligand by up to 0.8 A where it remains buried in a completely nonpolar environment. Isothermal titration calorimetry revealed that the binding of these compounds stabilizes the protein by 4-6 kcal/mol. For both polar and nonpolar ligands the binding is enthalpically driven. Large negative changes in entropy adversely balance the binding of the polar ligands, whereas entropy has little effect on the nonpolar ligand binding.

    Organizational Affiliation: 

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lysozyme
A, B
164Enterobacteria phage T4Mutation(s): 8 
Gene Names: E
EC: 3.2.1.17
Find proteins for P00720 (Enterobacteria phage T4)
Go to UniProtKB:  P00720
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT
Download SDF File 
Download CCD File 
A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL
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Download CCD File 
B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA
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Download CCD File 
B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
PYJ
Query on PYJ
Download SDF File 
Download CCD File 
A, B
PHENYLETHANE
C8 H10
YNQLUTRBYVCPMQ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CME
Query on CME
A, B
L-PEPTIDE LINKINGC5 H11 N O3 S2CYS
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
PYJKa: 22800 M-1 BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.07 Å
  • R-Value Free: 0.293 
  • R-Value Work: 0.237 
  • Space Group: P 43
Unit Cell:
Length (Å)Angle (°)
a = 49.274α = 90.00
b = 49.274β = 90.00
c = 129.332γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
Blu-Icedata collection
HKL-2000data scaling
HKL-2000data reduction
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots


View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-08-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Refinement description, Version format compliance
  • Version 1.2: 2013-12-25
    Type: Non-polymer description
  • Version 1.3: 2017-11-01
    Type: Refinement description