1I2P

CRYSTAL STRUCTURE OF ESCHERICHIA COLI TRANSALDOLASE B MUTANT D17A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.193 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Identification of catalytically important residues in the active site of Escherichia coli transaldolase.

Schorken, U.Thorell, S.Schurmann, M.Jia, J.Sprenger, G.A.Schneider, G.

(2001) Eur.J.Biochem. 268: 2408-2415

  • Primary Citation of Related Structures:  1I2N, 1I2O, 1I2Q, 1I2R

  • PubMed Abstract: 
  • The roles of invariant residues at the active site of transaldolase B from Escherichia coli have been probed by site-directed mutagenesis. The mutant enzymes D17A, N35A, E96A, T156A, and S176A were purified from a talB-deficient host and analyzed wit ...

    The roles of invariant residues at the active site of transaldolase B from Escherichia coli have been probed by site-directed mutagenesis. The mutant enzymes D17A, N35A, E96A, T156A, and S176A were purified from a talB-deficient host and analyzed with respect to their 3D structure and kinetic behavior. X-ray analysis showed that side chain replacement did not induce unanticipated structural changes in the mutant enzymes. Three mutations, N35A, E96A, and T156A resulted mainly in an effect on apparent kcat, with little changes in apparent Km values for the substrates. Residues N35 and T156 are involved in the positioning of a catalytic water molecule at the active site and the side chain of E96 participates in concert with this water molecule in proton transfer during catalysis. Substitution of Ser176 by alanine resulted in a mutant enzyme with 2.5% residual activity. The apparent Km value for the donor substrate, fructose 6-phosphate, was increased nearly fivefold while the apparent Km value for the acceptor substrate, erythrose 4-phosphate remained unchanged, consistent with a function for S176 in the binding of the C1 hydroxyl group of the donor substrate. The mutant D17A showed a 300-fold decrease in kcat, and a fivefold increase in the apparent Km value for the acceptor substrate erythrose 4-phosphate, suggesting a role of this residue in carbon-carbon bond cleavage and stabilization of the carbanion/enamine intermediate.


    Related Citations: 
    • Crystallization and Preliminary X-ray Analysis of Recombinant Transaldolase B from Escherichia coli
      Jia, J.,Lindqvist, Y.,Schneider, G.,Schoerken, U.,Sahm, H.,Sprenger, G.A.
      (1996) Acta Crystallogr.,Sect.D 52: 192
    • The Three-dimensional Structure of Human Transaldolase
      Thorell, S.,Gergely Jr., P.,Banki, K.,Perl, A.,Schneider, G.
      (2000) FEBS Lett. 475: 205
    • Crystal Structure of Transaldolase B from Escherichia coli Suggests a Circular Permutation of the Alpha/beta Barrel Within the Class I Aldolase Family
      Jia, J.,Huang, W.,Schoerken, U.,Sahm, H.,Sprenger, G.A.,Lindqvist, Y.,Schneider, G.
      (1996) Structure 4: 715
    • Crystal Structure of the Reduced Schiff-base Intermediate Complex of Transaldolase B from Escherichia coli: Mechanistic Implications for Class I Aldolases
      Jia, J.,Schoerken, U.,Lindqvist, Y.,Sprenger, G.A.,Schneider, G.
      (1997) Protein Sci. 6: 119


    Organizational Affiliation

    Institut für Biotechnologie 1, Forschungszentrum Jülich GmbH, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TRANSALDOLASE B
A, B
316Escherichia coli (strain K12)Gene Names: talB (yaaK)
EC: 2.2.1.2
Find proteins for P0A870 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A870
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.193 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 69.381α = 90.00
b = 92.788β = 90.00
c = 131.537γ = 90.00
Software Package:
Software NamePurpose
MAR345data collection
CNSphasing
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-05-09
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description