1F1B

CRYSTAL STRUCTURE OF E. COLI ASPARTATE TRANSCARBAMOYLASE P268A MUTANT IN THE R-STATE IN THE PRESENCE OF N-PHOSPHONACETYL-L-ASPARTATE

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

A cis-proline to alanine mutant of E. coli aspartate transcarbamoylase: kinetic studies and three-dimensional crystal structures.

Jin, L., Stec, B., Kantrowitz, E.R.

(2000) Biochemistry 39: 8058-8066

  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • The only cis-proline residue in Escherichia coli aspartate transcarbamoylase has been replaced by alanine using site-specific mutagenesis. The Pro268-->Ala enzyme exhibits a 40-fold reduction in enzyme activity and decreased substrate affinity toward ...

    The only cis-proline residue in Escherichia coli aspartate transcarbamoylase has been replaced by alanine using site-specific mutagenesis. The Pro268-->Ala enzyme exhibits a 40-fold reduction in enzyme activity and decreased substrate affinity toward carbamoyl phosphate and aspartate compared to the corresponding values for the wild-type enzyme. The concentration of the bisubstrate analogue N-phosphonacetyl-L-aspartate (PALA) required to activate the mutant enzyme to the same extent as the wild-type enzyme is significantly increased. The heterotropic effects of ATP and CTP upon the Pro268-->Ala enzyme are also altered. Crystal structures of the Pro268-->Ala enzyme in both T- and R-states show that the cis-peptidyl linkage between Leu267 and Ala268 is maintained. However, the tertiary structure of both the catalytic and regulatory chains has been altered by the amino acid substitution, and the mobility of the active-site residues is increased for the R-state structure of Pro268-->Ala enzyme as comparison with the wild-type R-state structure. These structural changes are responsible for the loss of enzyme activity. Thus, Pro268 is required for the proper positioning of catalytically critical residues in the active site and is important for the formation of the high-activity high-affinity R-state of E. coli aspartate transcarbamoylase.

    Related Citations: 
    • Insights into the Mechanism of Catalysis and Heterotropic Regulation of Escherichia coli Aspartate Transcarbamoylase based Upon a Structure of the Enzyme Complexed with the Bisubstrate Analog N-phosphonacetyl-L-aspartate at 2.1 A.
      Jin, L.,Stec, B.,Lipscomb, W.N.,Kantrowitz, E.R.
      (1999) PROTEINS: STRUCT.,FUNCT.,GENET. 37: 729

    Organizational Affiliation: 

    Department of Chemistry, Boston College, Merkert Chemistry Center, Chestnut Hill, Massachusetts 02467, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ASPARTATE CARBAMOYLTRANSFERASE CATALYTIC CHAIN
A, C
310Escherichia coli (strain K12)Mutations: A268P
Gene Names: pyrB
EC: 2.1.3.2
Find proteins for P0A786 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A786
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
ASPARTATE CARBAMOYLTRANSFERASE REGULATORY CHAIN
B, D
153Escherichia coli (strain K12)Gene Names: pyrI
Find proteins for P0A7F3 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A7F3
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PAL
Query on PAL
Download SDF File 
Download CCD File 
A, C
N-(PHOSPHONACETYL)-L-ASPARTIC ACID
C6 H10 N O8 P
ZZKNRXZVGOYGJT-VKHMYHEASA-N
 Ligand Interaction
ZN
Query on ZN
Download SDF File 
Download CCD File 
B, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.196 
  • Space Group: P 3 2 1
Unit Cell:
Length (Å)Angle (°)
a = 122.150α = 90.00
b = 122.150β = 90.00
c = 156.230γ = 120.00
Software Package:
Software NamePurpose
X-PLORmodel building
SDMSdata reduction
X-PLORrefinement
X-PLORphasing
SDMSdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-11-22
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance