1CQ4

CI2 MUTANT WITH TETRAGLUTAMINE (MGQQQQGM) REPLACING MET59


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.300 
  • R-Value Work: 0.240 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Crystal structure of a dimeric chymotrypsin inhibitor 2 mutant containing an inserted glutamine repeat.

Chen, Y.W.Stott, K.Perutz, M.F.

(1999) Proc Natl Acad Sci U S A 96: 1257-1261

  • DOI: https://doi.org/10.1073/pnas.96.4.1257
  • Primary Citation of Related Structures:  
    1CQ4

  • PubMed Abstract: 

    We have constructed mutants of chymotrypsin inhibitor 2 with short glutamine repeats inserted into its inhibitory loop. These mutants oligomerize when expressed in Escherichia coli. The dimer of a mutant with four glutamines now has been crystallized, and its structure has been solved by molecular replacement by using the wild-type monomer as a search model. The structure of each half of the dimer is found to be the same as that of the wild-type monomer, except around the glutamine insertion. It was proposed that the components of the oligomers are held together by hydrogen bonds between the main-chain and side-chain amides of the glutamine repeats. Instead, they appear to form by swapping domains on folding in E. coli, and the glutamine repeats connecting the components of the dimers are disordered.


  • Organizational Affiliation

    Centre for Protein Engineering, Medical Research Council Centre, Hills Road, Cambridge CB2 2QH, United Kingdom.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (SERINE PROTEINASE INHIBITOR 2)47Hordeum vulgareMutation(s): 1 
UniProt
Find proteins for P01053 (Hordeum vulgare)
Explore P01053 
Go to UniProtKB:  P01053
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01053
Sequence Annotations
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  • Reference Sequence

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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (SERINE PROTEINASE INHIBITOR 2)24Hordeum vulgareMutation(s): 0 
UniProt
Find proteins for P01053 (Hordeum vulgare)
Explore P01053 
Go to UniProtKB:  P01053
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01053
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth B]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.300 
  • R-Value Work: 0.240 
  • Space Group: P 6 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.267α = 90
b = 68.267β = 90
c = 60.833γ = 120
Software Package:
Software NamePurpose
AMoREphasing
REFMACrefinement
MOSFLMdata reduction
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-11-25
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2021-11-03
    Changes: Data collection, Database references, Derived calculations
  • Version 1.4: 2023-08-09
    Changes: Data collection, Refinement description