4HN4

Tryptophan synthase in complex with alpha aminoacrylate E(A-A) form and the F9 inhibitor in the alpha site


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.64 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.148 
  • R-Value Observed: 0.150 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


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: https://doi.org/10.1021/bi400795e
  • Primary Citation of Related Structures:  
    4HN4, 4HPJ, 4HPX, 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 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)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Tryptophan synthase alpha chain268Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Gene Names: STM1727trpAtrpA and trpB
EC: 4.2.1.20
UniProt
Find proteins for P00929 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P00929 
Go to UniProtKB:  P00929
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00929
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Tryptophan synthase beta chain397Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
EC: 4.2.1.20
UniProt
Find proteins for P0A2K1 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore P0A2K1 
Go to UniProtKB:  P0A2K1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0A2K1
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
F9F
Query on F9F

Download Ideal Coordinates CCD File 
C [auth A]2-({[4-(TRIFLUOROMETHOXY)PHENYL]SULFONYL}AMINO)ETHYL DIHYDROGEN PHOSPHATE
C9 H11 F3 N O7 P S
JDDKDMFCTOZVCJ-UHFFFAOYSA-N
0JO
Query on 0JO

Download Ideal Coordinates CCD File 
D [auth B]2-{[(E)-{3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}methylidene]amino}prop-2-enoic acid
C11 H13 N2 O7 P
BHIGINKEEFZJGX-YIXHJXPBSA-N
BCN
Query on BCN

Download Ideal Coordinates CCD File 
H [auth B],
I [auth B],
J [auth B]
BICINE
C6 H13 N O4
FSVCELGFZIQNCK-UHFFFAOYSA-N
CS
Query on CS

Download Ideal Coordinates CCD File 
K [auth B],
L [auth B]
CESIUM ION
Cs
NCMHKCKGHRPLCM-UHFFFAOYSA-N
PEG
Query on PEG

Download Ideal Coordinates CCD File 
E [auth B],
F [auth B],
G [auth B]
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.64 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.148 
  • R-Value Observed: 0.150 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 183.97α = 90
b = 59.72β = 94.69
c = 67.4γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-12-25
    Type: Initial release
  • Version 1.1: 2014-01-01
    Changes: Database references
  • Version 1.2: 2021-09-29
    Changes: Database references, Derived calculations
  • Version 1.3: 2023-09-20
    Changes: Data collection, Refinement description