1KRB

CRYSTAL STRUCTURE OF KLEBSIELLA AEROGENES UREASE, ITS APOENZYME AND TWO ACTIVE SITE MUTANTS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Work: 0.179 
  • R-Value Observed: 0.179 

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This is version 1.2 of the entry. See complete history


Literature

Structures of the Klebsiella aerogenes urease apoenzyme and two active-site mutants.

Jabri, E.Karplus, P.A.

(1996) Biochemistry 35: 10616-10626

  • DOI: https://doi.org/10.1021/bi960424z
  • Primary Citation of Related Structures:  
    1KRA, 1KRB, 1KRC

  • PubMed Abstract: 

    Urease from Klebsiella aerogenes [Jabri et al. (1995) Science 268, 998-1004] is an (alpha beta gamma)3 trimer with each alpha-subunit having an (alpha beta)8-barrel domain containing a binickel active center. Here we examine structure-function relations for urease in more detail through structural analysis of the urease apoenzyme at 2.3 A resolution and mutants of two key catalytic residues (H219A and H320A) at 2.5 A resolution. With the exception of the active site, in which a water molecule takes the place of the missing carbamate and nickel atoms, the structure of the apoenzyme is nearly identical to that of the holoenzyme, suggesting a high degree of preorganization which helps explain the tight binding of nickel. In the structure of H219A, the major change involves a conformational shift and ordering of the active site flap, but a small shift in the side chain of Asp alpha 221 could contribute to the lower activity of H219A. In the H320A structure, the catalytic water, primarily a Ni-2 ligand in the holoenzyme, shifts into a bridging position. This shift shows that the nickel ligation is rather sensitive to the environment and the change in ligation may contribute to the 10(5)-fold lower activity of H320A. In addition, these results show that urease is resilient to the loss of nickel ions and mutations. Analysis of the urease tertiary/quaternary structure suggests that the stability of this enzyme may be largely due to its burial of an unusually large fraction of its residues: 50% in the gamma-subunit, 30% in the beta-subunit, and 60% in the alpha-subunit.


  • Organizational Affiliation

    Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853, USA.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
UREASE100Klebsiella aerogenesMutation(s): 0 
EC: 3.5.1.5
UniProt
Find proteins for P18316 (Klebsiella aerogenes)
Explore P18316 
Go to UniProtKB:  P18316
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP18316
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
UREASE106Klebsiella aerogenesMutation(s): 0 
EC: 3.5.1.5
UniProt
Find proteins for P18315 (Klebsiella aerogenes)
Explore P18315 
Go to UniProtKB:  P18315
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP18315
Sequence Annotations
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
UREASE567Klebsiella aerogenesMutation(s): 0 
EC: 3.5.1.5
UniProt
Find proteins for P18314 (Klebsiella aerogenes)
Explore P18314 
Go to UniProtKB:  P18314
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP18314
Sequence Annotations
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
KCX
Query on KCX
C
L-PEPTIDE LINKINGC7 H14 N2 O4LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Work: 0.179 
  • R-Value Observed: 0.179 
  • Space Group: I 21 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 170.8α = 90
b = 170.8β = 90
c = 170.8γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1995-10-15
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance