1UX1

Bacillus subtilis cytidine deaminase with a Cys53His and an Arg56Gln substitution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.36 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.213 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural, Kinetic, and Mutational Studies of the Zinc Ion Environment in Tetrameric Cytidine Deaminase

Johansson, E.Neuhard, J.Willemoes, M.Larsen, S.

(2004) Biochemistry 43: 6020

  • DOI: 10.1021/bi035893x
  • Primary Citation of Related Structures:  
    1UX1, 1UX0, 1UWZ

  • PubMed Abstract: 
  • The zinc-containing cytidine deaminase (CDA, EC 3.5.4.5) is a pyrimidine salvage enzyme catalyzing the hydrolytic deamination of cytidine and 2'-deoxycytidine forming uridine and 2'-deoxyuridine, respectively. Homodimeric CDA (D-CDA) and homotetramer ...

    The zinc-containing cytidine deaminase (CDA, EC 3.5.4.5) is a pyrimidine salvage enzyme catalyzing the hydrolytic deamination of cytidine and 2'-deoxycytidine forming uridine and 2'-deoxyuridine, respectively. Homodimeric CDA (D-CDA) and homotetrameric CDA (T-CDA) both contain one zinc ion per subunit coordinated to the catalytic water molecule. The zinc ligands in D-CDA are one histidine and two cysteine residues, whereas in T-CDA zinc is coordinated to three cysteines. Two of the zinc coordinating cysteines in T-CDA form hydrogen bonds to the conserved residue Arg56, and this residue together with the dipole moments from two alpha-helices partially neutralizes the additional negative charge in the active site, leading to a catalytic activity similar to D-CDA. Arg56 has been substituted by a glutamine (R56Q), the corresponding residue in D-CDA, an alanine (R56A), and an aspartate (R56D). Moreover, one of the zinc-liganding cysteines has been substituted by histidine to mimic D-CDA, alone (C53H) and in combination with R56Q (C53H/R56Q). R56A, R56Q, and C53H/R56Q contain the same amount of zinc as the wild-type enzyme. The zinc-binding capacity of R56D is reduced. Only R56A, R56Q, and C53H/R56Q yielded measurable CDA activity, R56A and R56Q with similar K(m) but decreased V(max) values compared to wild-type enzyme. Because of dissociation into its inactive subunits, it was impossible to determine the kinetic parameters for C53H/R56Q. R56A and C53H/R56Q display increased apparent pK(a) values compared to the wild-type enzyme and R56Q. On the basis of the structures of R56A, R56Q, and C53H/R56Q an explanation is provided of kinetic results and the apparent instability of C53H/R56Q.


    Organizational Affiliation

    Centre for Crystallographic Studies, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark. eva@ccs.ki.ku.dk



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CYTIDINE DEAMINASEABCD136Bacillus subtilisMutation(s): 2 
EC: 3.5.4.5
Find proteins for P19079 (Bacillus subtilis (strain 168))
Explore P19079 
Go to UniProtKB:  P19079
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
THU
Query on THU

Download CCD File 
A, B, C, D
TETRAHYDRODEOXYURIDINE
C9 H14 N2 O5
XMJRLEURHMTTRX-FWHJPCMOSA-N
 Ligand Interaction
TRS
Query on TRS

Download CCD File 
A
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
ZN
Query on ZN

Download CCD File 
A, B, C, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.36 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.213 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.484α = 90
b = 62.484β = 90
c = 221.604γ = 120
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling
EPMRphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-05-20
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2019-03-06
    Changes: Data collection, Experimental preparation, Other