138L

RAPID CRYSTALLIZATION OF T4 LYSOZYME BY INTERMOLECULAR DISULFIDE CROSSLINKING


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Rapid crystallization of T4 lysozyme by intermolecular disulfide cross-linking.

Heinz, D.W.Matthews, B.W.

(1994) Protein Eng 7: 301-307

  • DOI: 10.1093/protein/7.3.301
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • In an attempt to facilitate crystallization, engineered cysteines were used to promote formation of a 'back-to-back' dimer that occurs in different crystal forms of wild-type and mutant T4 lysozymes. The designed double mutant, N68C/A93C, in which th ...

    In an attempt to facilitate crystallization, engineered cysteines were used to promote formation of a 'back-to-back' dimer that occurs in different crystal forms of wild-type and mutant T4 lysozymes. The designed double mutant, N68C/A93C, in which the surface residues Asn68 and Ala93 were replaced by cysteines, formed dimers in solution and crystallized isomorphously to wild-type, but at a much faster rate. Overall, the mutant structure remained very similar to wild-type despite the formation of two intermolecular disulfide bridges. The crystals of cross-linked dimers ahd thermal factors somewhat lower than wild-type, indicating reduced mobility, but did not diffract to noticeably higher resolution. Introduction of the same cross-links was also used to obtain crystals in a different space group of a T4 lysozyme mutant that could not be crystallized previously. The results suggest that the formation of the lysozyme dimer is a critical intermediate in the formation of more than one crystal form and that covalent cross-linking of the intermediate accelerates nucleation and facilitates crystal growth. The disulfide cross-links are located on the 'back' of the molecule and formation of the cross-linked dimer appears to leave the active sites completely unobstructed. Nevertheless, the cross-linked dimer is completely inactive. One explanation for this behavior is that the disulfide bridges prevent hinge-bending motion that may be required for catalysis. Another possibility is that the formation of the dimer increases the overall bulk of the enzyme and prevents its access to the susceptible glycosidic bonds within the cell wall substrate.


    Organizational Affiliation

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



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
T4 LYSOZYMEA164Escherichia virus T4Mutation(s): 0 
Gene Names: E
EC: 3.2.1.17
Find proteins for P00720 (Enterobacteria phage T4)
Explore P00720 
Go to UniProtKB:  P00720
Protein Feature View
 ( Mouse scroll to zoom / Hold left click to move )
  • 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: 1.70 Å
  • R-Value Observed: 0.173 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.82α = 90
b = 60.82β = 90
c = 97.24γ = 120
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

View Full Validation Report



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