1KNI

Stabilizing Disulfide Bridge Mutant of T4 Lysozyme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å

wwPDB Validation   3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Structure of a stabilizing disulfide bridge mutant that closes the active-site cleft of T4 lysozyme.

Jacobson, R.H.Matsumura, M.Faber, H.R.Matthews, B.W.

(1992) Protein Sci 1: 46-57

  • DOI: https://doi.org/10.1002/pro.5560010106
  • Primary Citation of Related Structures:  
    1KNI

  • PubMed Abstract: 

    The engineered disulfide bridge between residues 21 and 142 of phage T4 lysozyme spans the active-site cleft and can be used as a switch to control the activity of the enzyme (Matsumura, M. & Matthews, B.W., 1989, Science 243, 792-794). In the oxidized form the disulfide increases the melting temperature of the protein by 11 degrees C at pH 2. The crystal structure of this mutant lysozyme has been determined in both the reduced and oxidized forms. In the reduced form, the crystal structure of the mutant is shown to be extremely similar to that of wild type. In the oxidized form, however, the formation of the disulfide bridge causes the alpha-carbons of Cys 21 and Cys 142, on opposite sides of the active-site cleft, to move toward each other by 2.5 A. In association with this movement, the amino-terminal domain of the protein undergoes a rigid-body rotation of 5.1 degrees relative to the carboxy-terminal domain. This rotation occurs about an axis passing through the junction of the amino-terminal and carboxy-terminal domains and is also close to the axis that best fits the apparent thermal motion of the amino-terminal domain seen previously in crystals of wild-type lysozyme. Even though the engineered Cys 21-Cys 142 disulfide links together the amino-terminal and carboxy-terminal domains of T4 lysozyme, it does not reduce the apparent mobility of the one domain relative to the other. The pronounced "hinge-bending" mobility of the amino-terminal domain that is suggested by the crystallographic thermal parameters of wild-type lysozyme persists in the oxidized (and reduced) mutant structures. In the immediate vicinity of the introduced disulfide bridge the mutant structure is more mobile (or disordered) than wild type, so much so that the exact conformation of Cys 21 remains obscure. As with the previously described disulfide bridge between residues 9 and 164 of T4 lysozyme (Pjura, P.E., Matsumura, M., Wozniak, J.A., & Matthews, B.W., 1990, Biochemistry 29, 2592-2598), the engineered cross-link substantially enhances the stability of the protein without making the folded structure more rigid.


  • Organizational Affiliation

    Department of Physics, University of Oregon, Eugene 97403.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
LYSOZYME164Tequatrovirus T4Mutation(s): 4 
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
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.3α = 90
b = 62.3β = 90
c = 95.2γ = 120
Software Package:
Software NamePurpose
ROTAVATAdata reduction
TNTrefinement
AGROVATA / ROTAVATAdata scaling
AGROVATA / ROTAVATAdata scaling
TNTphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-12-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2020-07-22
    Changes: Advisory, Data collection, Other, Refinement description
  • Version 1.5: 2021-10-27
    Changes: Database references, Derived calculations