2J9X

Tryptophan Synthase in complex with GP, alpha-D,L-glycerol-phosphate, Cs, pH6.5 - alpha aminoacrylate form - (GP)E(A-A)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.215 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Allosteric Regulation of Substrate Channeling in Tryptophan Synthase: Modulation of the L-Serine Reaction in Stage I of the Beta-Reaction by Alpha-Site Ligands.

Ngo, H.Kimmich, N.Harris, R.Niks, D.Blumenstein, L.Kulik, V.Barends, T.R.Schlichting, I.Dunn, M.F.

(2007) Biochemistry 46: 7740

  • DOI: 10.1021/bi7003872
  • Primary Citation of Related Structures:  2CLL, 2CLM, 2CLO

  • PubMed Abstract: 
  • In the tryptophan synthase bienzyme complex, indole produced by substrate cleavage at the alpha-site is channeled to the beta-site via a 25 A long tunnel. Within the beta-site, indole and l-Ser react with pyridoxal 5'-phosphate in a two-stage reactio ...

    In the tryptophan synthase bienzyme complex, indole produced by substrate cleavage at the alpha-site is channeled to the beta-site via a 25 A long tunnel. Within the beta-site, indole and l-Ser react with pyridoxal 5'-phosphate in a two-stage reaction to give l-Trp. In stage I, l-Ser forms an external aldimine, E(Aex1), which converts to the alpha-aminoacrylate aldimine, E(A-A). Formation of E(A-A) at the beta-site activates the alpha-site >30-fold. In stage II, indole reacts with E(A-A) to give l-Trp. The binding of alpha-site ligands (ASLs) exerts strong allosteric effects on the reaction of substrates at the beta-site: the distribution of intermediates formed in stage I is shifted in favor of E(A-A), and the binding of ASLs triggers a conformational change in the beta-site to a state with an increased affinity for l-Ser. Here, we compare the behavior of new ASLs as allosteric effectors of stage I with the behavior of the natural product, d-glyceraldehyde 3-phosphate. Rapid kinetics and kinetic isotope effects show these ASLs bind with affinities ranging from micro- to millimolar, and the rate-determining step for conversion of E(Aex1) to E(A-A) is increased by 8-10-fold. To derive a structure-based mechanism for stage I, X-ray structures of both the E(Aex1) and E(A-A) states complexed with the different ASLs were determined and compared with structures of the ASL complexes with the internal aldimine [Ngo, H., Harris, R., Kimmich, N., Casino, P., Niks, D., Blumenstein, L., Barends, T. R., Kulik, V., Weyand, M., Schlichting, I., and Dunn, M. F. (2007) Biochemistry 46, 7713-7727].


    Organizational Affiliation

    Department of Biochemistry, University of California, Riverside, California 92521, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TRYPTOPHAN SYNTHASE ALPHA CHAIN
A
268Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Gene Names: trpA
EC: 4.2.1.20
Find proteins for P00929 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P00929
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
TRYPTOPHAN SYNTHASE BETA CHAIN
B
396Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Gene Names: trpB
EC: 4.2.1.20
Find proteins for P0A2K1 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P0A2K1
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
G3P
Query on G3P

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Download CCD File 
A
SN-GLYCEROL-3-PHOSPHATE
C3 H9 O6 P
AWUCVROLDVIAJX-GSVOUGTGSA-N
 Ligand Interaction
CS
Query on CS

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Download CCD File 
B
CESIUM ION
Cs
NCMHKCKGHRPLCM-UHFFFAOYSA-N
 Ligand Interaction
DMS
Query on DMS

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Download CCD File 
B
DIMETHYL SULFOXIDE
C2 H6 O S
IAZDPXIOMUYVGZ-UHFFFAOYSA-N
 Ligand Interaction
P1T
Query on P1T

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Download CCD File 
B
2-[({3-HYDROXY-2-METHYL-5-[(PHOSPHONOOXY)METHYL]PYRIDIN-4-YL}METHYL)AMINO]ACRYLIC ACID
C11 H15 N2 O7 P
BXUDKFHCAMQSRX-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.215 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 183.212α = 90.00
b = 59.621β = 94.63
c = 67.389γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
CNSrefinement
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-06-26
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance