4LNJ

Structure of Escherichia coli Threonine Aldolase in Unliganded Form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.209 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

On the catalytic mechanism and stereospecificity of Escherichia coli l-threonine aldolase.

di Salvo, M.L.Remesh, S.G.Vivoli, M.Ghatge, M.S.Paiardini, A.D'Aguanno, S.Safo, M.K.Contestabile, R.

(2014) FEBS J 281: 129-145

  • DOI: 10.1111/febs.12581
  • Primary Citation of Related Structures:  
    4LNJ, 4LNL, 4LNM

  • PubMed Abstract: 
  • L-threonine aldolases (L-TAs) represent a family of homologous pyridoxal 5'-phosphate-dependent enzymes found in bacteria and fungi, and catalyse the reversible cleavage of several L-3-hydroxy-α-amino acids. L-TAs have great biotechnological potential, as they catalyse the formation of carbon-carbon bonds, and therefore may be exploited for the bioorganic synthesis of L-3-hydroxyamino acids that are biologically active or constitute building blocks for pharmaceutical molecules ...

    L-threonine aldolases (L-TAs) represent a family of homologous pyridoxal 5'-phosphate-dependent enzymes found in bacteria and fungi, and catalyse the reversible cleavage of several L-3-hydroxy-α-amino acids. L-TAs have great biotechnological potential, as they catalyse the formation of carbon-carbon bonds, and therefore may be exploited for the bioorganic synthesis of L-3-hydroxyamino acids that are biologically active or constitute building blocks for pharmaceutical molecules. Many L-TAs, showing different stereospecificity towards the Cβ configuration, have been isolated. Because of their potential to carry out diastereoselective syntheses, L-TAs have been subjected to structural, functional and mechanistic studies. Nevertheless, their catalytic mechanism and the structural bases of their stereospecificity have not been elucidated. In this study, we have determined the crystal structure of low-specificity L-TA from Escherichia coli at 2.2-Å resolution, in the unliganded form and cocrystallized with L-serine and L-threonine. Furthermore, several active site mutants have been functionally characterized in order to elucidate the reaction mechanism and the molecular bases of stereospecificity. No active site catalytic residue was revealed, and a structural water molecule was assumed to act as the catalytic base in the retro-aldol cleavage reaction. Interestingly, the very large active site opening of E. coli L-TA suggests that much larger molecules than L-threonine isomers may be easily accommodated, and L-TAs may actually have diverse physiological functions in different organisms. Substrate recognition and reaction specificity seem to be guided by the overall microenvironment that surrounds the substrate at the enzyme active site, rather than by one ore more specific residues.


    Organizational Affiliation

    Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli', Sapienza Università di Roma, Italy.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Low-specificity L-threonine aldolaseA, B333Escherichia coli WV_060327Mutation(s): 0 
Gene Names: EcoM_01176ltaE
EC: 4.1.2.5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download Ideal Coordinates CCD File 
F [auth A],
I [auth B]
4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
 Ligand Interaction
PLR
Query on PLR

Download Ideal Coordinates CCD File 
E [auth A],
H [auth B]
(5-HYDROXY-4,6-DIMETHYLPYRIDIN-3-YL)METHYL DIHYDROGEN PHOSPHATE
C8 H12 N O5 P
RBCOYOYDYNXAFA-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
C [auth A],
D [auth A],
G [auth B]
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.209 
  • R-Value Observed: 0.209 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76.62α = 90
b = 100.79β = 90
c = 176.08γ = 90
Software Package:
Software NamePurpose
CNSrefinement
CrystalCleardata collection
d*TREKdata reduction
d*TREKdata scaling
CaspRphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-11-06
    Type: Initial release
  • Version 1.1: 2014-01-22
    Changes: Database references