4KKX

Crystal structure of Tryptophan Synthase from Salmonella typhimurium with 2-aminophenol quinonoid in the beta site and the F6 inhibitor in the alpha site


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.77 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.151 
  • R-Value Observed: 0.153 

wwPDB Validation 3D Report Full Report



Literature

Allostery and substrate channeling in the tryptophan synthase bienzyme complex: evidence for two subunit conformations and four quaternary states.

Niks, D.Hilario, E.Dierkers, A.Ngo, H.Borchardt, D.Neubauer, T.J.Fan, L.Mueller, L.J.Dunn, M.F.

(2013) Biochemistry 52: 6396-6411

  • DOI: 10.1021/bi400795e
  • Primary Citation of Related Structures:  
    4HN4, 4HPX, 4HPJ, 4HT3, 4KKX

  • PubMed Abstract: 
  • The allosteric regulation of substrate channeling in tryptophan synthase involves ligand-mediated allosteric signaling that switches the α- and β-subunits between open (low activity) and closed (high activity) conformations. This switching prevents t ...

    The allosteric regulation of substrate channeling in tryptophan synthase involves ligand-mediated allosteric signaling that switches the α- and β-subunits between open (low activity) and closed (high activity) conformations. This switching prevents the escape of the common intermediate, indole, and synchronizes the α- and β-catalytic cycles. (19)F NMR studies of bound α-site substrate analogues, N-(4'-trifluoromethoxybenzoyl)-2-aminoethyl phosphate (F6) and N-(4'-trifluoromethoxybenzenesulfonyl)-2-aminoethyl phosphate (F9), were found to be sensitive NMR probes of β-subunit conformation. Both the internal and external aldimine F6 complexes gave a single bound peak at the same chemical shift, while α-aminoacrylate and quinonoid F6 complexes all gave a different bound peak shifted by +1.07 ppm. The F9 complexes exhibited similar behavior, but with a corresponding shift of -0.12 ppm. X-ray crystal structures show the F6 and F9 CF3 groups located at the α-β subunit interface and report changes in both the ligand conformation and the surrounding protein microenvironment. Ab initio computational modeling suggests that the change in (19)F chemical shift results primarily from changes in the α-site ligand conformation. Structures of α-aminoacrylate F6 and F9 complexes and quinonoid F6 and F9 complexes show the α- and β-subunits have closed conformations wherein access of ligands into the α- and β-sites from solution is blocked. Internal and external aldimine structures show the α- and β-subunits with closed and open global conformations, respectively. These results establish that β-subunits exist in two global conformational states, designated open, where the β-sites are freely accessible to substrates, and closed, where the β-site portal into solution is blocked. Switching between these conformations is critically important for the αβ-catalytic cycle.


    Organizational Affiliation

    Department of Biochemistry, University of California at Riverside , Riverside, California 92521, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Tryptophan synthase alpha chainA268Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Gene Names: trpA
EC: 4.2.1.20
Find proteins for P00929 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P00929 
Go to UniProtKB:  P00929
Protein Feature View
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Tryptophan synthase beta chainB397Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Gene Names: trpB
EC: 4.2.1.20
Find proteins for P0A2K1 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P0A2K1 
Go to UniProtKB:  P0A2K1
Protein Feature View
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
AQ3
Query on AQ3

Download CCD File 
B
N-({3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}methyl)-3-[(2-hydroxyphenyl)amino]-D-alanine
C17 H22 N3 O8 P
SQQFVNZWYFZVSY-CQSZACIVSA-N
 Ligand Interaction
F6F
Query on F6F

Download CCD File 
A
2-{[4-(TRIFLUOROMETHOXY)BENZOYL]AMINO}ETHYL DIHYDROGEN PHOSPHATE
C10 H11 F3 N O6 P
YAHFSBJEYPSDPU-UHFFFAOYSA-N
 Ligand Interaction
PGE
Query on PGE

Download CCD File 
B
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
 Ligand Interaction
PEG
Query on PEG

Download CCD File 
A
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

Download CCD File 
A, B
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
NA
Query on NA

Download CCD File 
A, B
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.77 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.151 
  • R-Value Observed: 0.153 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 183.87α = 90
b = 61.46β = 94.7
c = 67.39γ = 90
Software Package:
Software NamePurpose
d*TREKdata scaling
SCALAdata scaling
MOLREPphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection
MOSFLMdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-01-01
    Type: Initial release