Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 18657.19 
• Atom Count: 1291 
• Residue Count: 164 
• Unique protein chains: 1

239L

THE RESPONSE OF T4 LYSOZYME TO LARGE-TO-SMALL SUBSTITUTIONS WITHIN THE CORE AND ITS RELATION TO THE HYDROPHOBIC EFFECT

• DOI: 10.2210/pdb239L/pdb

• Classification: HYDROLASE
• Organism(s): Enterobacteria phage T4
• Expression System: Escherichia coli
• Mutation(s): 3 


• Deposited: 1997-10-23 Released: 1998-03-18 
• Deposition Author(s): Xu, J., Baase, W.A., Baldwin, E., Matthews, B.W.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.8 Å
• R-Value Work: 0.160 

Literature

The response of T4 lysozyme to large-to-small substitutions within the core and its relation to the hydrophobic effect.

Xu, J., Baase, W.A., Baldwin, E., Matthews, B.W.

(1998) Protein Sci. 7: 158-177

• PubMed: 9514271 
• DOI: 10.1002/pro.5560070117
• Primary Citation of Related Structures:  
  251L, 250L, 249L, 248L, 247L, 246L, 245L, 244L, 243L, 242L, 241L, 240L, 238L, 237L, 236L, 235L


• PubMed Abstract: 
  

To further examine the structural and thermodynamic basis of hydrophobic stabilization in proteins, all of the bulky non-polar residues that are buried or largely buried within the core of T4 lysozyme were substituted with alanine. In 25 cases, including eight reported previously, it was possible to determine the crystal structures of the variants. The structures of four variants with double substitutions were also determined. In the majority of cases the "large-to-small" substitutions lead to internal cavities. In other cases declivities or channels open to the surface were formed. In some cases the structural changes were minimal (mainchain shifts < or = 0.3 A); in other cases mainchain atoms moved up to 2 A. In the case of Ile 29 --> Ala the structure collapsed to such a degree that the volume of the putative cavity was zero. Crystallographic analysis suggests that the occupancy of the engineered cavities by solvent is usually low. The mutants Val 149 --> Ala (V149A) and Met 6 --> Ala (M6A), however, are exceptions and have, respectively, one and two well-ordered water molecules within the cavity. The Val 149 --> Ala substitution allows the solvent molecule to hydrogen bond to polar atoms that are occluded in the wild-type molecule. Similarly, the replacement of Met 6 with alanine allows the two solvent molecules to hydrogen bond to each other and to polar atoms on the protein. Except for Val 149 --> Ala the loss of stability of all the cavity mutants can be rationalized as a combination of two terms. The first is a constant for a given class of substitution (e.g., -2.1 kcal/mol for all Leu --> Ala substitutions) and can be considered as the difference between the free energy of transfer of leucine and alanine from solvent to the core of the protein. The second term can be considered as the energy cost of forming the cavity and is consistent with a numerical value of 22 cal mol(-1) A(-3). Physically, this term is due to the loss of van der Waal's interactions between the bulky sidechain that is removed and the atoms that form the wall of the cavity. The overall results are consistent with the prior rationalization of Leu --> Ala mutants in T4 lysozyme by Eriksson et al. (Eriksson et al., 1992, Science 255:178-183).

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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
• Response of a Protein Structure to Cavity-Creating Mutations and its Relation to the Hydrophobic Effect
  Eriksson, A.E.,Baase, W.A.,Zhang, X.J.,Heinz, D.W.,Blaber, M.,Baldwin, E.P.,Matthews, B.W.
  (1992) Science 255: 178




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Organizational Affiliation: 

Howard Hughes Medical Institute and Department of Physics, University of Oregon, Eugene 97403, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
T4 LYSOZYME	A	164	Enterobacteria phage T4	Mutations: C97A, C54T, I17A Gene Names: E EC: 3.2.1.17
Find proteins for P00720 (Enterobacteria phage T4) Go to UniProtKB:  P00720

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
CL	A	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.8 Å
• R-Value Work: 0.160 
• Space Group: P 3₂ 2 1

Unit Cell:

Length (Å)	Angle (°)
a = 61.130	α = 90.00
b = 61.130	β = 90.00
c = 96.250	γ = 120.00

Software Package:

Software Name	Purpose
TNT	phasing
UCSD	data scaling
TNT	refinement
UCSD	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1997-10-23 
• Released Date: 1998-03-18 
• Deposition Author(s): Xu, J., Baase, W.A., Baldwin, E., Matthews, B.W.

Revision History 

• Version 1.0: 1998-03-18
  Type: Initial release
• Version 1.1: 2008-03-24
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance