1T36

Crystal structure of E. coli carbamoyl phosphate synthetase small subunit mutant C248D complexed with uridine 5'-monophosphate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.176 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Long-range allosteric transitions in carbamoyl phosphate synthetase.

Thoden, J.B.Huang, X.Kim, J.Raushel, F.M.Holden, H.M.

(2004) Protein Sci. 13: 2398-2405

  • DOI: 10.1110/ps.04822704

  • PubMed Abstract: 
  • Carbamoyl phosphate synthetase plays a key role in both pyrimidine and arginine biosynthesis by catalyzing the production of carbamoyl phosphate from one molecule of bicarbonate, two molecules of MgATP, and one molecule of glutamine. The enzyme from ...

    Carbamoyl phosphate synthetase plays a key role in both pyrimidine and arginine biosynthesis by catalyzing the production of carbamoyl phosphate from one molecule of bicarbonate, two molecules of MgATP, and one molecule of glutamine. The enzyme from Escherichia coli consists of two polypeptide chains referred to as the small and large subunits, which contain a total of three separate active sites that are connected by an intramolecular tunnel. The small subunit harbors one of these active sites and is responsible for the hydrolysis of glutamine to glutamate and ammonia. The large subunit binds the two required molecules of MgATP and is involved in assembling the final product. Compounds such as L-ornithine, UMP, and IMP allosterically regulate the enzyme. Here, we report the three-dimensional structure of a site-directed mutant protein of carbamoyl phosphate synthetase from E. coli, where Cys 248 in the small subunit was changed to an aspartate. This residue was targeted for a structural investigation because previous studies demonstrated that the partial glutaminase activity of the C248D mutant protein was increased 40-fold relative to the wild-type enzyme, whereas the formation of carbamoyl phosphate using glutamine as a nitrogen source was completely abolished. Remarkably, although Cys 248 in the small subunit is located at approximately 100 A from the allosteric binding pocket in the large subunit, the electron density map clearly revealed the presence of UMP, although this ligand was never included in the purification or crystallization schemes. The manner in which UMP binds to carbamoyl phosphate synthetase is described.


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbamoyl-phosphate synthase large chain
A, C, E, G
1073Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: carB (pyrA)
EC: 6.3.5.5
Find proteins for P00968 (Escherichia coli (strain K12))
Go to UniProtKB:  P00968
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Carbamoyl-phosphate synthase small chain
B, D, F, H
382Escherichia coli (strain K12)Mutation(s): 1 
Gene Names: carA (pyrA)
EC: 6.3.5.5
Find proteins for P0A6F1 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A6F1
Small Molecules
Ligands 8 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

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Download CCD File 
A, B, C, D, E, F, G, H
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
MN
Query on MN

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Download CCD File 
A, C, E, G
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
PO4
Query on PO4

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Download CCD File 
A, C, E, G
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
ADP
Query on ADP

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Download CCD File 
A, C, E, G
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A, C, D, E, F, G, H
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
U
Query on U

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Download CCD File 
A, C, E, G
URIDINE-5'-MONOPHOSPHATE
C9 H13 N2 O9 P
DJJCXFVJDGTHFX-XVFCMESISA-N
 Ligand Interaction
NET
Query on NET

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Download CCD File 
A, C, E, G
TETRAETHYLAMMONIUM ION
C8 H20 N
CBXCPBUEXACCNR-UHFFFAOYSA-N
 Ligand Interaction
ORN
Query on ORN

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Download CCD File 
A, C, E, G
L-ornithine
C5 H12 N2 O2
AHLPHDHHMVZTML-BYPYZUCNSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
UKd: 9000 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.176 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 152.500α = 90.00
b = 164.900β = 90.00
c = 333.100γ = 90.00
Software Package:
Software NamePurpose
TNTphasing
SCALEPACKdata scaling
TNTrefinement
d*TREKdata reduction
d*TREKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-09-21
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance