2pwe: Difference between revisions
New page: left|200px<br /><applet load="2pwe" size="350" color="white" frame="true" align="right" spinBox="true" caption="2pwe, resolution 2.0Å" /> '''Crystal structure of ... |
No edit summary |
||
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
Various diseases related to the | 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. | ||
==About this Structure== | ==About this Structure== | ||
| Line 10: | Line 10: | ||
==Reference== | ==Reference== | ||
Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization., Ravaud S, Robert X, Watzlawick H, Haser R, Mattes R, Aghajari N, J Biol Chem. 2007 Jun 27 | Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization., Ravaud S, Robert X, Watzlawick H, Haser R, Mattes R, Aghajari N, J Biol Chem. 2007 Sep 21;282(38):28126-36. Epub 2007 Jun 27. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17597061 17597061] | ||
[[Category: Isomaltulose synthase]] | [[Category: Isomaltulose synthase]] | ||
[[Category: Pseudomonas mesoacidophila]] | [[Category: Pseudomonas mesoacidophila]] | ||
| Line 27: | Line 27: | ||
[[Category: trehalulose synthase]] | [[Category: trehalulose synthase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:33:46 2008'' | ||
Revision as of 19:33, 21 February 2008
|
Crystal structure of the MutB E254Q mutant in complex with the substrate sucrose
OverviewOverview
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.
About this StructureAbout this Structure
2PWE is a Single protein structure of sequence from Pseudomonas mesoacidophila with and as ligands. Active as Isomaltulose synthase, with EC number 5.4.99.11 Full crystallographic information is available from OCA.
ReferenceReference
Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization., Ravaud S, Robert X, Watzlawick H, Haser R, Mattes R, Aghajari N, J Biol Chem. 2007 Sep 21;282(38):28126-36. Epub 2007 Jun 27. PMID:17597061
Page seeded by OCA on Thu Feb 21 18:33:46 2008