3CSU

CATALYTIC TRIMER OF ESCHERICHIA COLI ASPARTATE TRANSCARBAMOYLASE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.88 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Assessment of the allosteric mechanism of aspartate transcarbamoylase based on the crystalline structure of the unregulated catalytic subunit.

Beernink, P.T.Endrizzi, J.A.Alber, T.Schachman, H.K.

(1999) Proc.Natl.Acad.Sci.USA 96: 5388-5393

  • Also Cited By: 1GQ3

  • PubMed Abstract: 
  • The lack of knowledge of the three-dimensional structure of the trimeric, catalytic (C) subunit of aspartate transcarbamoylase (ATCase) has impeded understanding of the allosteric regulation of this enzyme and left unresolved the mechanism by which t ...

    The lack of knowledge of the three-dimensional structure of the trimeric, catalytic (C) subunit of aspartate transcarbamoylase (ATCase) has impeded understanding of the allosteric regulation of this enzyme and left unresolved the mechanism by which the active, unregulated C trimers are inactivated on incorporation into the unliganded (taut or T state) holoenzyme. Surprisingly, the isolated C trimer, based on the 1.9-A crystal structure reported here, resembles more closely the trimers in the T state enzyme than in the holoenzyme:bisubstrate-analog complex, which has been considered as the active, relaxed (R) state enzyme. Unlike the C trimer in either the T state or bisubstrate-analog-bound holoenzyme, the isolated C trimer lacks 3-fold symmetry, and the active sites are partially disordered. The flexibility of the C trimer, contrasted to the highly constrained T state ATCase, suggests that regulation of the holoenzyme involves modulating the potential for conformational changes essential for catalysis. Large differences in structure between the active C trimer and the holoenzyme:bisubstrate-analog complex call into question the view that this complex represents the activated R state of ATCase.


    Organizational Affiliation

    Department of Molecular and Cell Biology and Virus Laboratory, University of California, Berkeley, CA 94720-3206, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (ASPARTATE CARBAMOYLTRANSFERASE)
A, B, C
310Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: pyrB
EC: 2.1.3.2
Find proteins for P0A786 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A786
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
B, C
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.88 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.190 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 56.120α = 90.00
b = 82.540β = 90.00
c = 210.520γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
MOSFLMdata reduction
CCP4data scaling
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-05-11
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance