1L22

CONTRIBUTIONS OF LEFT-HANDED HELICAL RESIDUES TO THE STRUCTURE AND STABILITY OF BACTERIOPHAGE T4 LYSOZYME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.162 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Contributions of left-handed helical residues to the structure and stability of bacteriophage T4 lysozyme.

Nicholson, H.Soderlind, E.Tronrud, D.E.Matthews, B.W.

(1989) J Mol Biol 210: 181-193

  • DOI: https://doi.org/10.1016/0022-2836(89)90299-4
  • Primary Citation of Related Structures:  
    1L21, 1L22, 1L33

  • PubMed Abstract: 

    Non-glycine residues in proteins are rarely observed to have "left-handed helical" conformations. For glycine, however, this conformation is common. To determine the contributions of left-handed helical residues to the stability of a protein, two such residues in phage T4 lysozyme, Asn55 and Lys124, were replaced with glycine. The mutant proteins fold normally and are fully active, showing that left-handed non-glycine residues, although rare, do not have an indispensable role in the folding of the protein or in its activity. The thermodynamic stability of the Lys124 to Gly variant is essentially identical with that of wild-type lysozyme. The Asn55 to Gly mutant protein is marginally less stable (0.5 kcal/mol). These results indicate that the conformational energy of a glycine and a non-glycine residue in the left-handed helical conformation are very similar. This is consistent with some theoretical energy distributions, but is inconsistent with others, which suggest that replacements of the sort described here might increase the stability of the protein by up to 5 kcal/mol. Crystallographic analysis of the mutant proteins shows that the backbone conformation of the Lys124 to Gly variant is essentially identical with that of the wild-type structure. In the case of the Asn55 to Gly replacement, however, the (phi, psi) values of residue 55 change by about 20 degrees. This suggests that the energy minimum for left-handed glycine residues is not the same as that for non-glycine residues. This is strongly indicated also by a survey of accurately determined protein crystal structures, which suggests that the energy minimum for left-handed glycine residues is near (phi = 90 degrees, psi = 0 degrees), whereas that for non-glycine residues is close to (phi = 60 degrees, psi = 30 degrees). This apparent energy minimum for glycine is not clearly predicted by any of the theoretical (phi, psi) energy contour maps.


  • Organizational Affiliation

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


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
T4 LYSOZYME164Tequatrovirus T4Mutation(s): 1 
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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.162 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.6α = 90
b = 60.6β = 90
c = 96.4γ = 120
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • 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