2C3Z

Crystal structure of a truncated variant of indole-3-glycerol phosphate synthase from Sulfolobus solfataricus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Work: 0.180 
  • R-Value Observed: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Role of the N-Terminal Extension of the (Betaalpha)(8)-Barrel Enzyme Indole-3-Glycerol Phosphate Synthase for its Fold, Stability, and Catalytic Activity.

Schneider, B.Knoechel, T.Darimont, B.Hennig, M.Dietrich, S.Babinger, K.Kirschner, K.Sterner, R.

(2005) Biochemistry 44: 16405

  • DOI: 10.1021/bi051640n
  • Primary Citation of Related Structures:  
    2C3Z

  • PubMed Abstract: 
  • Indole-3-glycerol phosphate synthase (IGPS) catalyzes the fifth step in the biosynthesis of tryptophan. It belongs to the large and versatile family of (betaalpha)(8)-barrel enzymes but has an unusual N-terminal extension of about 40 residues. Limite ...

    Indole-3-glycerol phosphate synthase (IGPS) catalyzes the fifth step in the biosynthesis of tryptophan. It belongs to the large and versatile family of (betaalpha)(8)-barrel enzymes but has an unusual N-terminal extension of about 40 residues. Limited proteolysis with trypsin of IGPS from both Sulfolobus solfataricus (sIGPS) and Thermotoga maritima (tIGPS) removes about 25 N-terminal residues and one of the two extra helices contained therein. To assess the role of the extension, the N-terminally truncated variants sIGPSDelta(1-26) and tIGPSDelta(1-25) were produced recombinantly in Escherichia coli, purified, and characterized in comparison to the wild-type enzymes. Both sIGPSDelta(1-26) and tIGPSDelta(1-25) have unchanged oligomerization states and turnover numbers. In contrast, their Michaelis constants for the substrate 1-(o-carboxyphenylamino)-1-deoxyribulose 5-phosphate are increased, and their resistance toward unfolding induced by heat and guanidinium chloride is decreased. sIGPSDelta(1-26) was crystallized, and its X-ray structure was solved at 2.8 A resolution. The comparison with the known structure of sIGPS reveals small differences that account for its reduced substrate affinity and protein stability. The structure of the core of sIGPSDelta(1-26) is, however, unchanged compared to sIGPS, explaining its retained catalytic activity and consistent with the idea that it evolved from the same ancestor as the phosphoribosyl anthranilate isomerase and the alpha-subunit of tryptophan synthase. These (betaalpha)(8)-barrel enzymes catalyze the reactions preceding and following IGPS in tryptophan biosynthesis but lack an N-terminal extension.


    Organizational Affiliation

    Institut für Biophysik und physikalische Biochemie, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
INDOLE-3-GLYCEROL PHOSPHATE SYNTHASEA222Saccharolobus solfataricusMutation(s): 0 
EC: 4.1.1.48
Find proteins for Q06121 (Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2))
Explore Q06121 
Go to UniProtKB:  Q06121
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Work: 0.180 
  • R-Value Observed: 0.180 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.2α = 90
b = 61.4β = 90
c = 80.4γ = 90
Software Package:
Software NamePurpose
X-PLORrefinement
MOSFLMdata reduction
ROTAVATAdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-10-13
    Type: Initial release
  • Version 1.1: 2011-05-07
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance