1B7B

Carbamate kinase from Enterococcus faecalis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.283 
  • R-Value Work: 0.224 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Carbamate kinase: New structural machinery for making carbamoyl phosphate, the common precursor of pyrimidines and arginine.

Marina, A.Alzari, P.M.Bravo, J.Uriarte, M.Barcelona, B.Fita, I.Rubio, V.

(1999) Protein Sci 8: 934-940

  • DOI: 10.1110/ps.8.4.934
  • Primary Citation of Related Structures:  
    1B7B

  • PubMed Abstract: 
  • The enzymes carbamoyl phosphate synthetase (CPS) and carbamate kinase (CK) make carbamoyl phosphate in the same way: by ATP-phosphorylation of carbamate. The carbamate used by CK is made chemically, whereas CPS itself synthesizes its own carbamate in ...

    The enzymes carbamoyl phosphate synthetase (CPS) and carbamate kinase (CK) make carbamoyl phosphate in the same way: by ATP-phosphorylation of carbamate. The carbamate used by CK is made chemically, whereas CPS itself synthesizes its own carbamate in a process involving the phosphorylation of bicarbonate. Bicarbonate and carbamate are analogs and the phosphorylations are carried out by homologous 40 kDa regions of the 120 kDa CPS polypeptide. CK can also phosphorylate bicarbonate and is a homodimer of a 33 kDa subunit that was believed to resemble the 40 kDa regions of CPS. Such belief is disproven now by the CK structure reported here. The structure does not conform to the biotin carboxylase fold found in the 40 kDa regions of CPS, and presents a new type of fold possibly shared by homologous acylphosphate-making enzymes. A molecular 16-stranded open beta-sheet surrounded by alpha-helices is the hallmark of the CK dimer. Each subunit also contains two smaller sheets and a large crevice found at the location expected for the active center. Intersubunit interactions are very large and involve a central hydrophobic patch and more hydrophilic peripheral contacts. The crevice holds a sulfate that may occupy the site of an ATP phosphate, and is lined by conserved residues. Site-directed mutations tested at two of these residues inactivate the enzyme. These findings support active site location in the crevice. The orientation of the crevices in the dimer precludes their physical cooperation in the catalytic process. Such cooperation is not needed in the CK reaction but is a requirement of the mechanism of CPSs.


    Organizational Affiliation

    Instituto de Biomedicina de Valencia (CSIC), Spain.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CARBAMATE KINASEABCD310Enterococcus faeciumMutation(s): 0 
Gene Names: arcC1arcCarcC-1
EC: 2.7.2.2
Find proteins for P0A2X8 (Enterococcus faecium)
Explore P0A2X8 
Go to UniProtKB:  P0A2X8
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.283 
  • R-Value Work: 0.224 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 80.86α = 90
b = 172.92β = 90
c = 98.79γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-01-26
    Type: Initial release
  • Version 1.1: 2008-04-26
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance