1L20

ENHANCED PROTEIN THERMOSTABILITY FROM DESIGNED MUTATIONS THAT INTERACT WITH ALPHA-HELIX DIPOLES

• PDB DOI: https://doi.org/10.2210/pdb1L20/pdb

• Classification: HYDROLASE (O-GLYCOSYL)
• Organism(s): Tequatrovirus T4
• Mutation(s): Yes 


• Deposited: 1989-05-01 Released: 1990-01-15 
• Deposition Author(s): Nicholson, H., Matthews, B.W.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.85 Å
• R-Value Observed: 0.153 

Literature

Enhanced protein thermostability from designed mutations that interact with alpha-helix dipoles.

Nicholson, H., Becktel, W.J., Matthews, B.W.

(1988) Nature 336: 651-656

• PubMed: 3200317 
• DOI: https://doi.org/10.1038/336651a0
• Primary Citation of Related Structures:  
  1L19, 1L20


• PubMed Abstract: 
  

  Two different genetically engineered amino-acid substitutions designed to interact with alpha-helix dipoles in T4 lysozyme are shown to increase the thermal stability of the protein. Crystallographic analyses of the mutant lysozyme structures suggest that the stabilization is due to electrostatic interaction and does not require precise hydrogen bonding between the substituted amino acid and the end of the alpha-helix.

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Organizational Affiliation: 

Institute of Molecular Biology, University of Oregon, Eugene 97403.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 18.66 kDa 
• Atom Count: 1,461 
• Modelled Residue Count: 164 
• Deposited Residue Count: 164 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
T4 LYSOZYME	A	164	Tequatrovirus T4	Mutation(s): 1  EC: 3.2.1.17
UniProt
Find proteins for P00720 (Enterobacteria phage T4) Explore P00720  Go to UniProtKB:  P00720

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.85 Å
• R-Value Observed: 0.153 
• Space Group: P 3₂ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 61.1	α = 90
b = 61.1	β = 90
c = 97	γ = 120

Software Package:

Software Name	Purpose
TNT	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 1990-01-15 
Deposition Author(s): Nicholson, H., Matthews, B.W.

Revision History  

• Version 1.0: 1990-01-15
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Advisory, Version format compliance
• Version 1.3: 2017-11-29
  Changes: Derived calculations, Other
• Version 2.0: 2022-11-23
  Type: Remediation
  Changes: Advisory, Atomic model, Data collection, Database references, Other, Source and taxonomy
• Version 2.1: 2024-05-22
  Changes: Data collection