1I2O

CRYSTAL STRUCTURE OF ESCHERICHIA COLI TRANSALDOLASE B MUTANT E96A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.183 

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

  • DOI: 10.1046/j.1432-1327.2001.02128.x
  • Primary Citation of Related Structures:  
    1I2Q, 1I2P, 1I2O, 1I2N, 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 with respect to their 3D structure and kinetic behavior ...

    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 D Biol Crystallogr 52: 192
    • 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
    • The Three-dimensional Structure of Human Transaldolase
      Thorell, S., Gergely Jr., P., Banki, K., Perl, A., Schneider, G.
      (2000) FEBS Lett 475: 205

    Organizational Affiliation

    Institut für Biotechnologie 1, Forschungszentrum Jülich GmbH, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
TRANSALDOLASE B AB316Escherichia coliMutation(s): 1 
Gene Names: talB
EC: 2.2.1.2
Find proteins for P0A870 (Escherichia coli (strain K12))
Explore P0A870 
Go to UniProtKB:  P0A870
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.183 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.117α = 90
b = 91.99β = 90
c = 131.052γ = 90
Software Package:
Software NamePurpose
CNSrefinement
MAR345data collection
SCALEPACKdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

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