1QT3

T26D MUTANT OF T4 LYSOZYME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Work: 0.155 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural basis of the conversion of T4 lysozyme into a transglycosidase by reengineering the active site.

Kuroki, R.Weaver, L.H.Matthews, B.W.

(1999) Proc.Natl.Acad.Sci.USA 96: 8949-8954

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • In contrast to hen egg-white lysozyme, which retains the beta-configuration of the substrate in the product, T4 lysozyme (T4L) is an inverting glycosidase. The substitution Thr-26 --> His, however, converts T4L from an inverting to a retaining enzyme ...

    In contrast to hen egg-white lysozyme, which retains the beta-configuration of the substrate in the product, T4 lysozyme (T4L) is an inverting glycosidase. The substitution Thr-26 --> His, however, converts T4L from an inverting to a retaining enzyme. It is shown here that the Thr-26 --> His mutant is also a transglycosidase. Indeed, the transglycosylation reaction can be more effective than hydrolysis. In contrast, wild-type T4L has no detectable transglycosidase activity. The results support the prior hypothesis that catalysis by the Thr-26 --> His mutant proceeds via a covalent intermediate. Further mutations (Glu-11 --> His, Asp-20 --> Cys) of the T26H mutant lysozyme indicate that the catalytic mechanism of this mutant requires Glu-11 as a general acid but Asp-20 is not essential. The results help provide an overall rationalization for the activity of glycosidases, in which a highly conserved acid group (Glu-11 in T4L, Glu-35 in hen egg-white lysozyme) on the beta-side of the substrate acts as a proton donor, whereas alterations in the placement and chemical identity of residues on the alpha-side of the substrate can lead to catalysis with or without retention of the configuration, to transglycosidase activity, or to the formation of a stable enzyme-substrate adduct.


    Related Citations: 
    • Structure of Bacteriophage T4 Lysozyme Refined at 1.7 A Resolution
      Weaver, L.H.,Matthews, B.W.
      (1987) J.Mol.Biol. 193: 189
    • Structure-based Design of a Lysozyme with Altered Catalytic Activity
      Kuroki, R.,Weaver, L.H.,Matthews, B.W.
      (1995) Nat.Struct.Mol.Biol. 2: 1007


    Organizational Affiliation

    Central Laboratories for Key Technology, Kirin Brewery Co., Ltd., 1-13-5, Fukuura, Kanazawa-ku, Yokohama 236 Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (T4 Lysozyme)
A
164Enterobacteria phage T4Mutations: C97A, C54T, T26D
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
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
HED
Query on HED

Download SDF File 
Download CCD File 
A
2-HYDROXYETHYL DISULFIDE
C4 H10 O2 S2
KYNFOMQIXZUKRK-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Work: 0.155 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 60.900α = 90.00
b = 60.900β = 90.00
c = 96.900γ = 120.00
Software Package:
Software NamePurpose
TNTrefinement
TNTphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-07-08
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description