Crystal Structure of the Trehalulose Synthase MutB From Pseudomonas Mesoacidophila MX-45 Complexed to the Inhibitor Castanospermine

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.186 

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Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization.

Ravaud, S.Robert, X.Watzlawick, H.Haser, R.Mattes, R.Aghajari, N.

(2007) J Biol Chem 61: 100-103

  • DOI: https://doi.org/10.1074/jbc.M704515200
  • Primary Citation of Related Structures:  
    1ZJA, 2PWD, 2PWE, 2PWF, 2PWG, 2PWH

  • PubMed Abstract: 

    Various diseases related to the overconsumption of sugar make a growing need for sugar substitutes. Because sucrose is an inexpensive and readily available d-glucose donor, the industrial potential for enzymatic synthesis of the sucrose isomers trehalulose and/or isomaltulose from sucrose is large. The product specificity of sucrose isomerases that catalyze this reaction depends essentially on the possibility for tautomerization of sucrose, which is required for trehalulose formation. For optimal use of the enzyme, targeting controlled synthesis of these functional isomers, it is necessary to minimize the side reactions. This requires an extensive analysis of substrate binding modes and of the specificity-determining sites in the structure. The 1.6-2.2-A resolution three-dimensional structures of native and mutant complexes of a trehalulose synthase from Pseudomonas mesoacidophila MX-45 mimic successive states of the enzyme reaction. Combined with mutagenesis studies they give for the first time thorough insights into substrate recognition and processing and reaction specificities of these enzymes. Among the important outcomes of this study is the revelation of an aromatic clamp defined by Phe(256) and Phe(280) playing an essential role in substrate recognition and in controlling the reaction specificity, which is further supported by mutagenesis studies. Furthermore, this study highlights essential residues for binding the glucosyl and fructosyl moieties. The introduction of subtle changes informed by comparative three-dimensional structural data observed within our study can lead to fundamental modifications in the mode of action of sucrose isomerases and hence provide a template for industrial catalysts.

  • Organizational Affiliation

    Laboratoire de BioCristallographie, Institut de Biologie et Chimie des Protéines, CNRS et Université de Lyon, UMR 5086, IFR 128 BioSciences Gerland-Lyon Sud, F-69367 Lyon Cedex 07, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Sucrose isomerase
A, B
556Burkholderia ubonensis subsp. mesacidophilaMutation(s): 0 
Gene Names: mutB
Find proteins for Q2PS28 (Burkholderia ubonensis subsp. mesacidophila)
Explore Q2PS28 
Go to UniProtKB:  Q2PS28
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ2PS28
Sequence Annotations
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
CTS PDBBind:  2PWG Ki: 1.50e+4 (nM) from 1 assay(s)
Binding MOAD:  2PWG Ki: 1.50e+4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.186 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.24α = 90
b = 85.96β = 99.2
c = 123.52γ = 90
Software Package:
Software NamePurpose
MAR345data collection
XDSdata reduction
XSCALEdata 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: 2007-06-26
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description
  • Version 1.4: 2023-08-30
    Changes: Data collection, Database references, Derived calculations, Refinement description