1L36

TOWARD A SIMPLIFICATION OF THE PROTEIN FOLDING PROBLEM: A STABILIZING POLYALANINE ALPHA-HELIX ENGINEERED IN T4 LYSOZYME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.164 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Toward a simplification of the protein folding problem: a stabilizing polyalanine alpha-helix engineered in T4 lysozyme.

Zhang, X.J.Baase, W.A.Matthews, B.W.

(1991) Biochemistry 30: 2012-2017

  • DOI: https://doi.org/10.1021/bi00222a001
  • Primary Citation of Related Structures:  
    1L36

  • PubMed Abstract: 

    In an attempt to simplify the protein folding problem, and also to further investigate the role of alanine as a helix-stabilizing residue, a series of alanines was introduced within the alpha-helix that includes residues 126-134 of T4 lysozyme. In wild-type lysozyme this alpha-helix contains alanine residues at positions 129, 130, and 134. Mutant lysozymes with alanines substituted at positions 128, 131, 132, and 133, either as single substitutions or in selected combinations, were constructed by oligonucleotide-directed mutagenesis. With the exception of the replacement of Leu 133, which is buried within the hydrophobic core of the protein, all the variants were more stable than wild-type lysozyme. The variant with alanines substituted at positions 128, 131, and 132 (E128A/V131A/N132A), which incorporates the sequence Ala 128-Ala 129-Ala 130-Ala 131-Ala 132-Leu 133-Ala 134, has a melting temperature 3.3 degrees C above that of wild-type lysozyme. Determination of the crystal structure of this mutant lysozyme shows that the replacement of Glu 128, Val 131, and Asn 132 with alanine causes alpha-helix 126-134 to rotate 3.4 degrees about an axis parallel to its own axis. This rotation seems to be triggered primarily by the loss of a hydrogen bond between Asn 132 and Ser 117 and is associated with the repacking of several side chains at the interface between alpha-helix 126-134 and the adjacent alpha-helix 115-122.(ABSTRACT TRUNCATED AT 250 WORDS)


  • 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
LYSOZYME164Tequatrovirus T4Mutation(s): 3 
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
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Observed: 0.164 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.3α = 90
b = 61.3β = 90
c = 96.3γ = 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: 1991-10-15
    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, Derived calculations, Other