Glycoside Hydrolase Family 11 - Revision history

Harry Brumer at 16:40, 29 July 2015

2015-07-29T16:40:25Z

Harry Brumer at 16:32, 29 July 2015

2015-07-29T16:32:03Z

Harry Brumer at 16:24, 29 July 2015

2015-07-29T16:24:31Z

Harry Brumer: /* Kinetics and Mechanism */

2013-08-27T15:32:12Z

Kinetics and Mechanism

Harry Brumer: /* Kinetics and Mechanism */

2013-08-27T15:31:50Z

Kinetics and Mechanism

Harry Brumer: updated CAZyDBlink

2012-09-10T16:32:22Z

updated CAZyDBlink

Spencer Williams at 11:47, 14 June 2010

2010-06-14T11:47:17Z

Harry Brumer at 08:40, 17 May 2010

2010-05-17T08:40:19Z

Harry Brumer at 16:04, 27 April 2010

2010-04-27T16:04:17Z

Harry Brumer at 13:54, 8 November 2009

2009-11-08T13:54:59Z

@@ Line 26: / Line 26: @@
 == Substrate specificities ==
-The [[glycoside hydrolases]] of this family are [[endo]]-β-1,4-xylanases. No other activities have been observed.  As a historical note, GH11 was one of the first glycoside hydrolase families classified by sequence analysis, and was previously known as "Cellulase Family G" prior to detailed enzymological characterization <cite>Gilkes1991</cite>.
+The [[glycoside hydrolases]] of this family are [[endo]]-β-1,4-xylanases. No other activities have been observed.  As a historical note, GH11 was one of the first glycoside hydrolase families classified by sequence analysis, and was previously known as "Cellulase Family G" prior to extensive enzymological characterization <cite>Gilkes1991</cite>.
 == Kinetics and Mechanism ==

@@ Line 26: / Line 26: @@
 == Substrate specificities ==
-The [[glycoside hydrolases]] of this family are [[endo]]-β-1,4-xylanases. No other activities have been observed.  As a historical note, GH11 was one of the first glycoside hydrolase families classified by sequence analysis, and was previously known as "Cellulase Family G" prior to detailed enzymological charaterization <cite>Henrissat1989 Gilkes1991</cite>.
+The [[glycoside hydrolases]] of this family are [[endo]]-β-1,4-xylanases. No other activities have been observed.  As a historical note, GH11 was one of the first glycoside hydrolase families classified by sequence analysis, and was previously known as "Cellulase Family G" prior to detailed enzymological characterization <cite>Gilkes1991</cite>.
 == Kinetics and Mechanism ==
@@ Line 57: / Line 57: @@
 #10 pmid=9416621
 #11 pmid=10752613
 #Gilkes1991 pmid=1886523
 </biblio>
 [[Category:Glycoside Hydrolase Families|GH011]]

@@ Line 26: / Line 26: @@
 == Substrate specificities ==
-The [[glycoside hydrolases]] of this family are [[endo]]-β-1,4-xylanases. No other activities have been observed.
+The [[glycoside hydrolases]] of this family are [[endo]]-β-1,4-xylanases. No other activities have been observed.  As a historical note, GH11 was one of the first glycoside hydrolase families classified by sequence analysis, and was previously known as "Cellulase Family G" prior to detailed enzymological charaterization <cite>Henrissat1989 Gilkes1991</cite>.
 == Kinetics and Mechanism ==
@@ Line 56: / Line 56: @@
 #9 pmid=8762143
 #10 pmid=9416621
 #11 pmid=10752613
 </biblio>
 [[Category:Glycoside Hydrolase Families|GH011]]

@@ Line 29: / Line 29: @@
 == Kinetics and Mechanism ==
-[[Image:xylanase.png|thumb|right|500px|'''Figure.''' Xylanase reaction.]]
+[[Image:xylanase.png|thumb|right|600px|'''Figure.''' Xylanase reaction.]]
 Family GH11 xylanases are [[retaining]] enzymes, as first shown by NMR <cite>1</cite> and follow a classical [[Koshland double-displacement mechanism]]. No detailed analyses involving both steady state and pre-steady state kinetic studies have been reported. However, recent studies of the contributions of each substrate hydroxyl to [[transition state]] stabilization, and thus to catalysis, have been reported <cite>2</cite>.

@@ Line 29: / Line 29: @@
 == Kinetics and Mechanism ==
-[[Image:xylanase.png|thumb|right|500px|'''Figure. Xylanase reaction''']]
+[[Image:xylanase.png|thumb|right|500px|'''Figure.''' Xylanase reaction.]]
 Family GH11 xylanases are [[retaining]] enzymes, as first shown by NMR <cite>1</cite> and follow a classical [[Koshland double-displacement mechanism]]. No detailed analyses involving both steady state and pre-steady state kinetic studies have been reported. However, recent studies of the contributions of each substrate hydroxyl to [[transition state]] stabilization, and thus to catalysis, have been reported <cite>2</cite>.
 == Catalytic Residues ==

@@ Line 21: / Line 21: @@
 |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
 |-
-| colspan="2" |http://www.cazy.org/fam/GH11.html
+| colspan="2" |{{CAZyDBlink}}GH11.html
 |}
 </div>

@@ Line 30: / Line 30: @@
 == Kinetics and Mechanism ==
 [[Image:xylanase.png|thumb|right|500px|'''Figure. Xylanase reaction''']]
-Family GH11 xylanases are [[retaining]] enzymes, as first shown by NMR <cite>1</cite> and follow a classical [[Koshland double-displacement mechanism]]. No detailed analyses involving both steady state and pre-steady state kinetic studies have been reported. However, recent studies of the contributions of each substrate hydroxyl to transition state binding, and thus to catalysis, have been reported <cite>2</cite>.
+Family GH11 xylanases are [[retaining]] enzymes, as first shown by NMR <cite>1</cite> and follow a classical [[Koshland double-displacement mechanism]]. No detailed analyses involving both steady state and pre-steady state kinetic studies have been reported. However, recent studies of the contributions of each substrate hydroxyl to [[transition state]] stabilization, and thus to catalysis, have been reported <cite>2</cite>.
 == Catalytic Residues ==
-The [[catalytic nucleophile]] was first identified in the ''Bacillus circulans'' [[endo]]-xylanase as Glu78 in the sequence IT'''<u>E</u>'''LD through trapping of the 2-deoxy-2-fluoroxylobiosyl-enzyme [[intermediate]] and subsequent peptide mapping via LC-MS/MS technologies <cite>3</cite>. The importance of the precise positioning of the nucleophile was probed by detailed kinetic analysis of mutants modified at that position <cite>4</cite>. The [[general acid/base]] catalyst was first identified as Glu127 in this same enzyme through detailed mechanistic analysis of mutants at that position, which included azide rescue experiments <cite>5</cite>. Indeed detailed analyses of the role of the [[general acid/base]] catalyst have been described. NMR measurements of changes in pK<sub>a</sub> values of enzymic residues during the catalytic cycle reveal pK<sub>a</sub> cycling <cite>6</cite>, while the changes that occur upon repositioning or removing the acid/base residue reveal its contributions <cite>7Lawson</cite>.
+The [[catalytic nucleophile]] was first identified in the ''Bacillus circulans'' [[endo]]-xylanase as Glu78 in the sequence IT'''<u>E</u>'''LD through trapping of the 2-deoxy-2-fluoroxylobiosyl-enzyme [[intermediate]] and subsequent peptide mapping via LC-MS/MS technologies <cite>3</cite>. The importance of the precise positioning of the nucleophile was probed by detailed kinetic analysis of mutants modified at that position <cite>4</cite>. The [[general acid/base]] residue was first identified as Glu127 in this same enzyme through detailed mechanistic analysis of mutants at that position, which included azide rescue experiments <cite>5</cite>. Indeed detailed analyses of the role of the [[general acid/base]] catalyst have been described. NMR measurements of changes in pK<sub>a</sub> values of enzymic residues during the catalytic cycle reveal pK<sub>a</sub> cycling <cite>6</cite>, while the changes that occur upon repositioning or removing the [[general acid/base]] residue reveal its contributions <cite>7Lawson</cite>.
 == Three-dimensional structures ==

@@ Line 49: / Line 49: @@
 #2 pmid=17503782
 #3 pmid=7911679
-#4 pmid=8756474 NUC
+#4 pmid=8756474
 #5 pmid=7910761
 #6 pmid=8756457

← Older revision		Revision as of 13:54, 8 November 2009
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		+	{{CuratorApproved}}
	* [[Author]]: [[User:Withers\|Stephen Withers]]		* [[Author]]: [[User:Withers\|Stephen Withers]]
	* [[Responsible Curator]]: [[User:Withers\|Stephen Withers]]		* [[Responsible Curator]]: [[User:Withers\|Stephen Withers]]