CAZypedia - User contributions [en-ca]

User:Maxime Versluys

2017-02-04T08:26:25Z

Maxime Versluys:

[[Image:Maxime_Versluys.jpg|150px|right]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

User:Maxime Versluys

2017-02-04T08:23:44Z

Maxime Versluys:

User:Maxime Versluys

2017-02-04T08:23:32Z

Maxime Versluys:

User:Maxime Versluys

2017-02-04T08:23:18Z

Maxime Versluys:

User:Maxime Versluys

2017-02-04T08:22:56Z

Maxime Versluys:

[[Image:Maxime_Versluys.jpg|110px|right]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

User:Maxime Versluys

2017-02-04T08:22:43Z

Maxime Versluys:

[[Image:Maxime_Versluys.jpg|130px|right]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

User:Maxime Versluys

2017-02-04T08:22:28Z

Maxime Versluys:

User:Maxime Versluys

2017-02-04T08:22:05Z

Maxime Versluys:

[[Image:Maxime_Versluys.jpg|200px|right]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

File:Maxime Versluys.jpg

2017-02-04T08:21:41Z

Maxime Versluys:

User:Maxime Versluys

2017-02-04T08:19:21Z

Maxime Versluys:

[[Image:User-Maxime_Versluys.JPG|200px|right]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

User:Maxime Versluys

2017-02-04T08:18:43Z

Maxime Versluys:

[[Image:User-Maxime_Versluys.JPG|200px|thumb|right|alt text]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

User:Maxime Versluys

2017-02-04T08:17:45Z

Maxime Versluys:

[[User-Maxime_Versluys.JPG|200px|thumb|right|alt text]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

User:Maxime Versluys

2017-02-04T08:17:19Z

Maxime Versluys:

[[File:User-Maxime_Versluys.JPG|200px|thumb|right|alt text]]

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32]] and [[GH68]], is also investigated <cite>Versluys2017</cite>.

----
<biblio>
#Versluys2017 pmid=28123393
</biblio>

[[Category:Contributors|Versluys, Maxime]]

Glycoside Hydrolase Family 68

2017-02-03T09:46:47Z

Maxime Versluys: /* References */

{{CuratorApproved}}
* [[Author]]: ^^^Tirso Pons^^^, ^^^Maxime Versluys^^^, and ^^^Wim Van den Ende^^^
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''
|-
|'''Clan'''
|GH-J
|-
|'''Mechanism'''
|retaining
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH68.html
|}
</div>


== Substrate specificities ==
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio).

== Kinetics and Mechanism ==
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.

== Catalytic Residues ==
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.

== Three-dimensional structures ==
Currently, only six different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, the third corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>, the fourth is an inulosucrase (InuJ) from ''Lactobacillus johnsonii'' NCC533 <cite>Pijning2011</cite> and the fifth one corresponds to beta-fructofuranosidase (ArFFase) from Arthrobacter sp. K-1 <cite>Tonozuca2012</cite>. Lately, the three dimensional structure of a levansucrase from ''Erwinia amylovora'' has been characterized as well <cite>Wuerges2015</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.

== Family Firsts ==
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.

== References ==
<biblio>
#Koshland1954 pmid=13174523
#Chambert1974 pmid=4206083
#Chambert1976 pmid=814002
#Hernandez1995 pmid=7619044
#Song1999 pmid=10393084
#Meng2003 pmid=14517548
#Yanase2002 pmid=12359071
#Batista1999 pmid=9895294
#Isono2004 pmid=16233623
#Ozimek2004 pmid=14988011
#MartinezFleites2005 pmid=15869470
#Naumoff2001 pmid=11093261
#Pons1998 pmid=9829697
#Pons2000 pmid=11305239
#Strube2011 pmid=21454585
#Pijning2011 pmid=21801732
#Tonozuca2012 pmid=23040392
#Wuerges2015 pmid=26208466
</biblio>

[[Category:Glycoside Hydrolase Families|GH068]]

Glycoside Hydrolase Family 68

2017-02-03T09:45:15Z

Maxime Versluys: /* Three-dimensional structures */

{{CuratorApproved}}
* [[Author]]: ^^^Tirso Pons^^^, ^^^Maxime Versluys^^^, and ^^^Wim Van den Ende^^^
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''
|-
|'''Clan'''
|GH-J
|-
|'''Mechanism'''
|retaining
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH68.html
|}
</div>


== Substrate specificities ==
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio).

== Kinetics and Mechanism ==
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.

== Catalytic Residues ==
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.

== Three-dimensional structures ==
Currently, only six different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, the third corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>, the fourth is an inulosucrase (InuJ) from ''Lactobacillus johnsonii'' NCC533 <cite>Pijning2011</cite> and the fifth one corresponds to beta-fructofuranosidase (ArFFase) from Arthrobacter sp. K-1 <cite>Tonozuca2012</cite>. Lately, the three dimensional structure of a levansucrase from ''Erwinia amylovora'' has been characterized as well <cite>Wuerges2015</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.

== Family Firsts ==
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.

== References ==
<biblio>
#Koshland1954 pmid=13174523
#Chambert1974 pmid=4206083
#Chambert1976 pmid=814002
#Hernandez1995 pmid=7619044
#Song1999 pmid=10393084
#Meng2003 pmid=14517548
#Yanase2002 pmid=12359071
#Batista1999 pmid=9895294
#Isono2004 pmid=16233623
#Ozimek2004 pmid=14988011
#MartinezFleites2005 pmid=15869470
#Naumoff2001 pmid=11093261
#Pons1998 pmid=9829697
#Pons2000 pmid=11305239
#Strube2011 pmid=21454585
#Pijning2011 pmid=21801732
#Tonozuca2012 pmid=23040392
</biblio>

[[Category:Glycoside Hydrolase Families|GH068]]

Glycoside Hydrolase Family 68

2017-02-03T09:44:22Z

Maxime Versluys: /* Three-dimensional structures */

{{CuratorApproved}}
* [[Author]]: ^^^Tirso Pons^^^, ^^^Maxime Versluys^^^, and ^^^Wim Van den Ende^^^
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''
|-
|'''Clan'''
|GH-J
|-
|'''Mechanism'''
|retaining
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH68.html
|}
</div>


== Substrate specificities ==
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio).

== Kinetics and Mechanism ==
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.

== Catalytic Residues ==
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.

== Three-dimensional structures ==
Currently, only six different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, the third corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>, the fourth is an inulosucrase (InuJ) from ''Lactobacillus johnsonii'' NCC533 <cite>Pijning2011</cite> and the fifth one corresponds to beta-fructofuranosidase (ArFFase) from Arthrobacter sp. K-1 <cite>Tonozuca2012</cite>. Lately, the three dimensional structure of a levansucrase from ''Erwinia amylovora'' has been characterized as well<cite>Wuerges2015</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.

== Family Firsts ==
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.

== References ==
<biblio>
#Koshland1954 pmid=13174523
#Chambert1974 pmid=4206083
#Chambert1976 pmid=814002
#Hernandez1995 pmid=7619044
#Song1999 pmid=10393084
#Meng2003 pmid=14517548
#Yanase2002 pmid=12359071
#Batista1999 pmid=9895294
#Isono2004 pmid=16233623
#Ozimek2004 pmid=14988011
#MartinezFleites2005 pmid=15869470
#Naumoff2001 pmid=11093261
#Pons1998 pmid=9829697
#Pons2000 pmid=11305239
#Strube2011 pmid=21454585
#Pijning2011 pmid=21801732
#Tonozuca2012 pmid=23040392
</biblio>

[[Category:Glycoside Hydrolase Families|GH068]]

Glycoside Hydrolase Family 68

2017-02-03T09:40:19Z

Maxime Versluys: /* Three-dimensional structures */

{{CuratorApproved}}
* [[Author]]: ^^^Tirso Pons^^^, ^^^Maxime Versluys^^^, and ^^^Wim Van den Ende^^^
* [[Responsible Curator]]: ^^^Wim Van den Ende^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH68'''
|-
|'''Clan'''
|GH-J
|-
|'''Mechanism'''
|retaining
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH68.html
|}
</div>


== Substrate specificities ==
[[Glycoside hydrolase]] family 68 enzymes include levansucrase (sucrose:2,6-β-D-fructan 6-β-D-fructosyltransferase; EC [{{EClink}}2.4.1.10 2.4.1.10]), β-fructofuranosidase (EC [{{EClink}}3.2.1.26 3.2.1.26]), and inulosucrase (EC [{{EClink}}2.4.1.9 2.4.1.9]). All these enzymes use sucrose as their preferential donor substrate. Many of them can create very long levan-type fructans (catalyzed by levansucrases) or inulin-type of fructans (catalyzed by inulosucrases), as well as fructooligosacharides (FOS). However, some GH68 enzymes can also use fructan as donor substrate (in the abscence of sucrose or at a high fructan/sucrose ratio).

== Kinetics and Mechanism ==
Family GH68 enzymes as well as those included in [[GH32]] are [[retaining]] enzymes <cite>Koshland1954</cite>. The levansucrases from ''Bacillus subtilis'', ''Gluconacetobacter diazotrophicus'', and ''Streptococcus salivarius'' catalyze transfructosylation via a ping-pong mechanism involving the formation of a transient fructosyl-enzyme intermediate <cite>Chambert1974 Cambert1976 Hernandez1995 Song1999</cite>. At low sucrose concentrations levansucrase functions as a hydrolase with water as acceptor, whereas at higher substrate concentrations it adds fructosyl units to a variety of acceptors including glucose, fructan and sucrose <cite>Chambert1974</cite>. Bacterial levansucrases, whatever their origin, catalyze all these reactions but with different efficiency.

== Catalytic Residues ==
GH68 [[retaining]] enzymes catalyze hydrolysis in two steps involving a covalent glycosyl enzyme [[intermediate]]. The two invariant residues, responsible for the catalytic reaction in family GH68 enzymes, have first been identified experimentally in bacterial levansucrases as an aspartate located close to the N-terminus acting as the [[catalytic nucleophile]] and a glutamate acting as the [[general acid/base]] <cite>Meng2003 Yanase2002</cite>. In addition, a conserved aspartate residue in the "Arg-Asp-Pro (RDP) motif" stabilizes the [[transition state]] <cite>Song1999 Yanase2002 Batista1999</cite>. The three equivalent acidic residues have been mutated in a β-fructofuranosidase from ''Arthrobacter globiformis'' IFO 3062 <cite>Isono2004</cite>, and in a levansucrase and a inulosucrase from ''Lactobacillus reuteri'' 121 <cite>Ozimek2004</cite>.

== Three-dimensional structures ==
Currently, only six different three dimensional structures of family GH68 enzymes have been solved. The first crystal structure was reported for the bacterial levansucrase (SacB) from ''Bacillus subtilis'' subsp. subtilis str. 168 <cite>Meng2003</cite>. The second one corresponds to levansucrase (LdsA) from ''Gluconacetobacter diazotrophicus'' SRT4 <cite>MartinezFleites2005</cite>, the third corresponds to SacB from ''Bacillus megaterium'' <cite>Strube2011</cite>, the fourth is an inulosucrase (InuJ) from ''Lactobacillus johnsonii'' NCC533 <cite>Pijning2011</cite> and the fifth one corresponds to beta-fructofuranosidase (ArFFase) from Arthrobacter sp. K-1 <cite>Tonozuca2012</cite>. Lately, the three dimensional structure of a levansucrose from ''Erwinia amylovora'' has been characterized as well<cite>Wuerges2015</cite>. These structures display a 5-fold β-propeller topology, and therefore GH families 68 and [[GH32|32]] have been combined in clan GH-J. On the other hand, a structural relationship of the catalytic core exists to family GH68 and family [[GH43]], as predicted by detailed sequence analysis<cite>Naumoff2001</cite>.

== Family Firsts ==
;First stereochemistry determination: ''Bacillus subtilis'' levansucrase <cite>Chambert1974</cite>.
;First [[catalytic nucleophile]] identification: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.
;First [[general acid/base]] residue identification: ''Zymomonas mobilis'' levansucrase <cite>Yanase2002</cite>.
;First stabilizing [[transition state]] residue identification: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Batista1999</cite>.
;First prediction of a common beta-propeller catalytic domain in GH68 / clan GH-J: ''Gluconacetobacter diazotrophicus'' levansucrase <cite>Pons1998 Pons2000</cite>.
;First 3-D structure: ''Bacillus subtilis'' levansucrase <cite>Meng2003</cite>.

== References ==
<biblio>
#Koshland1954 pmid=13174523
#Chambert1974 pmid=4206083
#Chambert1976 pmid=814002
#Hernandez1995 pmid=7619044
#Song1999 pmid=10393084
#Meng2003 pmid=14517548
#Yanase2002 pmid=12359071
#Batista1999 pmid=9895294
#Isono2004 pmid=16233623
#Ozimek2004 pmid=14988011
#MartinezFleites2005 pmid=15869470
#Naumoff2001 pmid=11093261
#Pons1998 pmid=9829697
#Pons2000 pmid=11305239
#Strube2011 pmid=21454585
#Pijning2011 pmid=21801732
#Tonozuca2012 pmid=23040392
</biblio>

[[Category:Glycoside Hydrolase Families|GH068]]

User:Maxime Versluys

2017-02-03T08:58:04Z

Maxime Versluys: /* References */

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]], KU Leuven).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]], is also investigated <cite>Versluys2017</cite>.

== ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:57:49Z

Maxime Versluys: /* Referencess */

User:Maxime Versluys

2017-02-03T08:57:25Z

Maxime Versluys: /* References */

User:Maxime Versluys

2017-02-03T08:51:59Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:51:32Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology] (Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]], is also investigated <cite>Versluys2017</cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:51:12Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]], is also investigated <cite>Versluys2017</cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:50:43Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [[User:Wim_Van_den_Ende|Wim Van den Ende]]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated <cite>Versluys2017</cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:50:08Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [[user:wim van den ende|Wim Van den Ende]]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated <cite>Versluys2017</cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:48:44Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated <cite>Versluys2017</cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:48:21Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated<cite>Versluys2017</cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:47:37Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants<cite>Versluys2017<cite>. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:46:56Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=28123393
<biblio>

User:Maxime Versluys

2017-02-03T08:45:17Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=5225100
<biblio>

User:Maxime Versluys

2017-02-03T08:44:46Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated <cite>Versluys2017<cite>.

== '''Reference'''s ==
<biblio>
#Versluys2017 pmid=5225100
<biblio>

User:Maxime Versluys

2017-02-03T08:41:18Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated <cite>Versluys2017<cite>.

User:Maxime Versluys

2017-02-03T08:26:15Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[GH32|GH32]] and [[GH68|GH68]] is also investigated.

User:Maxime Versluys

2017-02-03T08:24:08Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[glycoside hydrolase family 32|GH32]] and [[glycoside hydrolase family 68|GH68]] is also investigated.

User:Maxime Versluys

2017-02-03T08:23:08Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [[glycoside hydrolase family 68|GH68]] and [https://www.cazypedia.org/index.php/Glycoside_Hydrolase_Family_68 GH68] is also investigated.

User:Maxime Versluys

2017-02-03T08:21:00Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [https://bio.kuleuven.be/pf/molecular_plant_biology lab of Molecular Plant Biology]
<br/>(Prof. [https://www.cazypedia.org/index.php/User:Wim_Van_den_Ende Wim Van den Ende]).

I focus on the role of fructan metabolism during (a)biotic stress in plants. This involves fructan priming experiments in different plant species and subsequent measurement of disease tolerance. The role of sugar metabolic enzymes, including members of the glycoside hydrolase families [https://www.cazypedia.org/index.php/Glycoside_Hydrolase_Family_32 GH32] and [https://www.cazypedia.org/index.php/Glycoside_Hydrolase_Family_68 GH68] is also investigated.

User:Maxime Versluys

2017-02-03T08:15:03Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:11:09Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:10:45Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:08:55Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:07:52Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:07:11Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:05:15Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T08:03:38Z

Maxime Versluys:

User:Maxime Versluys

2017-02-03T07:59:55Z

Maxime Versluys:

I obtained my master in Biology at KU Leuven (Leuven, Belgium) in 2016. Currently, I'm a predoctoral student in the [lab of Molecular Plant Biology]

User:Maxime Versluys

2017-02-03T07:57:08Z

Maxime Versluys: Created page with "Maxime Versluys"

Maxime Versluys