Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Hetero 4-mer - A2B2 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 71.60 kDa 
• Atom Count: 5386 
• Residue Count: 662 
• Unique protein chains: 2

1KFE

CRYSTAL STRUCTURE OF ALPHAT183V MUTANT OF TRYPTOPHAN SYNTHASE FROM SALMONELLA TYPHIMURIUM WITH L-Ser Bound To The Beta Site

• DOI: 10.2210/pdb1KFE/pdb

• Classification: LYASE
• Organism(s): Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica serovar Typhimurium str. LT2
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2001-11-20 Released: 2003-01-07 
• Deposition Author(s): Kulik, V., Weyand, M., Siedel, R., Niks, D., Arac, D., Dunn, M.F., Schlichting, I.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.75 Å
• R-Value Free: 0.225 
• R-Value Work: 0.192 
• R-Value Observed: 0.192 

Literature

On the Role of AlphaTHR183 in the Allosteric Regulation and Catalytic Mechanism of Tryptophan Synthase

Kulik, V., Weyand, M., Siedel, R., Niks, D., Arac, D., Dunn, M.F., Schlichting, I.

(2002) J Mol Biol 324: 677-690

• PubMed: 12460570 
• DOI: 10.1016/s0022-2836(02)01109-9
• Primary Citation of Related Structures:  
  1KFC, 1KFB, 1KFK, 1KFJ, 1KFE, 1K8X


• PubMed Abstract: 
  

The catalytic activity and substrate channeling of the pyridoxal 5'-phosphate-dependent tryptophan synthase alpha(2)beta(2) complex is regulated by allosteric interactions that modulate the switching of the enzyme between open, low activity and closed, high activity states during the catalytic cycle. The highly conserved alphaThr183 residue is part of loop alphaL6 and is located next to the alpha-active site and forms part of the alpha-beta subunit interface. The role of the interactions of alphaThr183 in alpha-site catalysis and allosteric regulation was investigated by analyzing the kinetics and crystal structures of the isosteric mutant alphaThr183Val. The mutant displays strongly impaired allosteric alpha-beta communication, and the catalytic activity of the alpha-reaction is reduced one hundred fold, whereas the beta-activity is not affected. The structural work establishes that the basis for the missing inter-subunit signaling is the lack of loop alphaL6 closure even in the presence of the alpha-subunit ligands, 3-indolyl-D-glycerol 3'-phosphate, or 3-indolylpropanol 3'-phosphate. The structural basis for the reduced alpha-activity has its origins in the missing hydrogen bond between alphaThr183 and the catalytic residue, alphaAsp60.

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Organizational Affiliation: 

Max Planck Institut für Molekulare Physiologie, Abeilung für Biophysikalische Chemie, Otto Hahn Str 11, 44227 Dortmund, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TRYPTOPHAN SYNTHASE ALPHA CHAIN	A	268	Salmonella enterica subsp. enterica serovar Typhimurium	Mutation(s): 1  EC: 4.2.1.20
Find proteins for P00929 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)) Explore P00929  Go to UniProtKB:  P00929

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
TRYPTOPHAN SYNTHASE BETA CHAIN	B	394	Salmonella enterica subsp. enterica serovar Typhimurium str. LT2	Mutation(s): 0  Gene Names: trpB, STM1726 EC: 4.2.1.20
Find proteins for P0A2K1 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)) Explore P0A2K1  Go to UniProtKB:  P0A2K1

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PLS	B	[3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-YLMETHYL]-SERINE C11 H17 N2 O8 P ODVKKQWXKRZJLG-VIFPVBQESA-N
NA	B	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.75 Å
• R-Value Free: 0.225 
• R-Value Work: 0.192 
• R-Value Observed: 0.192 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 182.224	α = 90
b = 59.985	β = 94.68
c = 67.072	γ = 90

Software Package:

Software Name	Purpose
MAR	data collection
XDS	data reduction
CNS	refinement
MAR	data reduction
XDS	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2001-11-20 
• Released Date: 2003-01-07 
Deposition Author(s): Kulik, V., Weyand, M., Siedel, R., Niks, D., Arac, D., Dunn, M.F., Schlichting, I.

Revision History 

• Version 1.0: 2003-01-07
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Source and taxonomy, Version format compliance