1LBF

CRYSTAL STRUCTURE OF INDOLE-3-GLYCEROL PHOSPHATE SYNTASE (IGPS)WITH REDUCED 1-(O-CABOXYPHENYLAMINO)-1-DEOXYRIBULOSE 5-PHOSPHATE (RCDRP)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.152 
  • R-Value Observed: 0.160 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The catalytic mechanism of indole-3-glycerol phosphate synthase: crystal structures of complexes of the enzyme from Sulfolobus solfataricus with substrate analogue, substrate, and product.

Hennig, M.Darimont, B.D.Jansonius, J.N.Kirschner, K.

(2002) J Mol Biol 319: 757-766

  • DOI: https://doi.org/10.1016/S0022-2836(02)00378-9
  • Primary Citation of Related Structures:  
    1A53, 1LBF, 1LBL

  • PubMed Abstract: 

    Indoleglycerol phosphate synthase catalyzes the ring closure of an N-alkylated anthranilate to a 3-alkyl indole derivative, a reaction requiring Lewis acid catalysis in vitro. Here, we investigated the enzymatic reaction mechanism through X-ray crystallography of complexes of the hyperthermostable enzyme from Sulfolobus solfataricus with the substrate 1-(o-carboxyphenylamino) 1-deoxyribulose 5-phosphate, a substrate analogue and the product indole-3-glycerol phosphate. The substrate and the substrate analogue are bound to the active site in a similar, extended conformation between the previously identified phosphate binding site and a hydrophobic pocket for the anthranilate moiety. This binding mode is unproductive, because the carbon atoms that are to be joined are too far apart. The indole ring of the bound product resides in a second hydrophobic pocket adjacent to that of the anthranilate moiety of the substrate. Although the hydrophobic moiety of the substrate moves during catalysis from one hydrophobic pocket to the other, the triosephosphate moiety remains rigidly bound to the same set of hydrogen-bonding residues. Simultaneously, the catalytically important residues Lys53, Lys110 and Glu159 maintain favourable distances to the atoms of the ligand undergoing covalent changes. On the basis of these data, the structures of two putative catalytic intermediates were modelled into the active site. This new structural information and the modelling studies provide further insight into the mechanism of enzyme-catalyzed indole synthesis. The charged epsilon-amino group of Lys110 is the general acid, and the carboxylate group of Glu159 is the general base. Lys53 guides the substrate undergoing conformational transitions during catalysis, by forming a salt-bridge to the carboxylate group of its anthranilate moiety.


  • Organizational Affiliation

    Division Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland. michael.hennig@roche.com


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
INDOLE-3-GLYCEROL PHOSPHATE SYNTHASE247Saccharolobus solfataricusMutation(s): 0 
EC: 4.1.1.48
UniProt
Find proteins for Q06121 (Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2))
Explore Q06121 
Go to UniProtKB:  Q06121
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ06121
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
137
Query on 137

Download Ideal Coordinates CCD File 
B [auth A]1-(O-CARBOXY-PHENYLAMINO)-1-DEOXY-D-RIBULOSE-5-PHOSPHATE
C12 H18 N O9 P
AULMJMUNCOBRHC-MXWKQRLJSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
137 PDBBind:  1LBF Kd: 14 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.152 
  • R-Value Observed: 0.160 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.8α = 90
b = 73.7β = 90
c = 104.4γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
MOSFLMdata reduction
CCP4data scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-06-12
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-16
    Changes: Data collection, Database references, Derived calculations, Refinement description