Loop-inserted Structure of P1-P1' Cleaved Ovalbumin Mutant R339T

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.199 

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Loop-inserted and thermostabilized structure of P1-P1' cleaved ovalbumin mutant R339T.

Yamasaki, M.Arii, Y.Mikami, B.Hirose, M.

(2002) J Mol Biol 315: 113-120

  • DOI: https://doi.org/10.1006/jmbi.2001.5056
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Ovalbumin is a member of a superfamily of serine proteinase inhibitors, known as the serpins. It is, however, non-inhibitory towards serine proteinases, and lacks the loop insertion mechanism common to the serpins due to unknown structural factors. Mutant ovalbumin, R339T, in which the P14 hinge residue is replaced, was produced and analyzed for its thermostability and three-dimensional structure. Differential scanning calorimetry revealed that the mutant ovalbumin, but not the wild-type protein, undergoes a marked thermostabilization (DeltaT(m)=15.8 degrees C) following the P1-P1' cleavage. Furthermore, the crystal structure, solved at 2.3 A resolution, clearly proved that the P1-P1' cleaved form assumes the fully loop-inserted conformation as seen in serpin that possess inhibitory activity. We therefore conclude that ovalbumin acquires the structural transition mechanism into the loop-inserted, thermostabilized form by the single hinge mutation. The mutant protein does not, however, possess inhibitory activity. The solved structure displays the occurrence of specific interactions that may prevent the smooth motion, relative to sheet A, of helices E and F and of the loop that follows helix F. These observations provide crucial insights into the question why R339T is still non-inhibitory.

  • Organizational Affiliation

    Division of Applied Life Sciences, Kyoto University, Japan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
385Gallus gallusMutation(s): 0 
Gene Names: ovalbumin
Find proteins for P01012 (Gallus gallus)
Explore P01012 
Go to UniProtKB:  P01012
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01012
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.199 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.714α = 89.11
b = 65.465β = 63.27
c = 68.422γ = 61.72
Software Package:
Software NamePurpose
SADIEdata collection
SAINTdata reduction
SADIEdata reduction
SAINTdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-09-05
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance