2d5j: Difference between revisions

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[[Image:2d5j.gif|left|200px]]<br /><applet load="2d5j" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:2d5j.gif|left|200px]]<br /><applet load="2d5j" size="350" color="white" frame="true" align="right" spinBox="true"

caption="2d5j, resolution 1.60Å" />

'''Unsaturated Glucuronyl Hydrolase Triggers Hydration of Vinyl Ether Group but not of Glycosidic Bond'''<br />

==Overview==

Unsaturated glucuronyl hydrolase (UGL), which is a member of glycoside, hydrolase family GH-88, is a bacterial enzyme that degrades mammalian, glycosaminoglycans and bacterial biofilms. The enzyme, which acts on, unsaturated oligosaccharides with an alpha-glycoside bond produced by, microbial polysaccharide lyases responsible for bacterial invasion of host, cells, was believed to release 4-deoxy-l-threo-5-hexosulose-uronate, (unsaturated glucuronic acid, or DeltaGlcA) and saccharide with a new, nonreducing terminus by hydrolyzing the glycosidic bond. We detail the, crystal structures of wild-type inactive mutant UGL of Bacillus sp. GL1, and its complex with a substrate (unsaturated chondroitin disaccharide), identify active site residues, and postulate a reaction mechanism, catalyzed by UGL that triggers the hydration of the vinyl ether group in, DeltaGlcA, based on the structural analysis of the enzyme-substrate, complex and biochemical analysis. The proposed catalytic mechanism of UGL, is a novel case among known glycosidases. Under the proposed mechanism, Asp-149 acts as a general acid and base catalyst to protonate the, DeltaGlcA C4 atom and to deprotonate the water molecule. The deprotonated, water molecule attacks the DeltaGlcA C5 atom to yield unstable hemiketal;, this is followed by spontaneous conversion to an aldehyde, (4-deoxy-l-threo-5-hexosulose-uronate) and saccharide through hemiacetal, formation and cleavage of the glycosidic bond. UGL is the first clarified, alpha(6)/alpha(6)-barrel enzyme using aspartic acid as the general, acid/base catalyst.

Unsaturated glucuronyl hydrolase (UGL), which is a member of glycoside hydrolase family GH-88, is a bacterial enzyme that degrades mammalian glycosaminoglycans and bacterial biofilms. The enzyme, which acts on unsaturated oligosaccharides with an alpha-glycoside bond produced by microbial polysaccharide lyases responsible for bacterial invasion of host cells, was believed to release 4-deoxy-l-threo-5-hexosulose-uronate (unsaturated glucuronic acid, or DeltaGlcA) and saccharide with a new nonreducing terminus by hydrolyzing the glycosidic bond. We detail the crystal structures of wild-type inactive mutant UGL of Bacillus sp. GL1 and its complex with a substrate (unsaturated chondroitin disaccharide), identify active site residues, and postulate a reaction mechanism catalyzed by UGL that triggers the hydration of the vinyl ether group in DeltaGlcA, based on the structural analysis of the enzyme-substrate complex and biochemical analysis. The proposed catalytic mechanism of UGL is a novel case among known glycosidases. Under the proposed mechanism, Asp-149 acts as a general acid and base catalyst to protonate the DeltaGlcA C4 atom and to deprotonate the water molecule. The deprotonated water molecule attacks the DeltaGlcA C5 atom to yield unstable hemiketal; this is followed by spontaneous conversion to an aldehyde (4-deoxy-l-threo-5-hexosulose-uronate) and saccharide through hemiacetal formation and cleavage of the glycosidic bond. UGL is the first clarified alpha(6)/alpha(6)-barrel enzyme using aspartic acid as the general acid/base catalyst.

==About this Structure==

2D5J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=2D5J OCA].

2D5J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2D5J OCA].

==Reference==

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[[Category: unsaturated glucuronyl hydrolase]]

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@@ Line 1: / Line 1: @@
-[[Image:2d5j.gif|left|200px]]<br /><applet load="2d5j" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2d5j.gif|left|200px]]<br /><applet load="2d5j" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2d5j, resolution 1.60&Aring;" />
 '''Unsaturated Glucuronyl Hydrolase Triggers Hydration of Vinyl Ether Group but not of Glycosidic Bond'''<br />
 ==Overview==
-Unsaturated glucuronyl hydrolase (UGL), which is a member of glycoside, hydrolase family GH-88, is a bacterial enzyme that degrades mammalian, glycosaminoglycans and bacterial biofilms. The enzyme, which acts on, unsaturated oligosaccharides with an alpha-glycoside bond produced by, microbial polysaccharide lyases responsible for bacterial invasion of host, cells, was believed to release 4-deoxy-l-threo-5-hexosulose-uronate, (unsaturated glucuronic acid, or DeltaGlcA) and saccharide with a new, nonreducing terminus by hydrolyzing the glycosidic bond. We detail the, crystal structures of wild-type inactive mutant UGL of Bacillus sp. GL1, and its complex with a substrate (unsaturated chondroitin disaccharide), identify active site residues, and postulate a reaction mechanism, catalyzed by UGL that triggers the hydration of the vinyl ether group in, DeltaGlcA, based on the structural analysis of the enzyme-substrate, complex and biochemical analysis. The proposed catalytic mechanism of UGL, is a novel case among known glycosidases. Under the proposed mechanism, Asp-149 acts as a general acid and base catalyst to protonate the, DeltaGlcA C4 atom and to deprotonate the water molecule. The deprotonated, water molecule attacks the DeltaGlcA C5 atom to yield unstable hemiketal;, this is followed by spontaneous conversion to an aldehyde, (4-deoxy-l-threo-5-hexosulose-uronate) and saccharide through hemiacetal, formation and cleavage of the glycosidic bond. UGL is the first clarified, alpha(6)/alpha(6)-barrel enzyme using aspartic acid as the general, acid/base catalyst.
+Unsaturated glucuronyl hydrolase (UGL), which is a member of glycoside hydrolase family GH-88, is a bacterial enzyme that degrades mammalian glycosaminoglycans and bacterial biofilms. The enzyme, which acts on unsaturated oligosaccharides with an alpha-glycoside bond produced by microbial polysaccharide lyases responsible for bacterial invasion of host cells, was believed to release 4-deoxy-l-threo-5-hexosulose-uronate (unsaturated glucuronic acid, or DeltaGlcA) and saccharide with a new nonreducing terminus by hydrolyzing the glycosidic bond. We detail the crystal structures of wild-type inactive mutant UGL of Bacillus sp. GL1 and its complex with a substrate (unsaturated chondroitin disaccharide), identify active site residues, and postulate a reaction mechanism catalyzed by UGL that triggers the hydration of the vinyl ether group in DeltaGlcA, based on the structural analysis of the enzyme-substrate complex and biochemical analysis. The proposed catalytic mechanism of UGL is a novel case among known glycosidases. Under the proposed mechanism, Asp-149 acts as a general acid and base catalyst to protonate the DeltaGlcA C4 atom and to deprotonate the water molecule. The deprotonated water molecule attacks the DeltaGlcA C5 atom to yield unstable hemiketal; this is followed by spontaneous conversion to an aldehyde (4-deoxy-l-threo-5-hexosulose-uronate) and saccharide through hemiacetal formation and cleavage of the glycosidic bond. UGL is the first clarified alpha(6)/alpha(6)-barrel enzyme using aspartic acid as the general acid/base catalyst.
 ==About this Structure==
-D5J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2D5J OCA].
+D5J is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2D5J OCA].
 ==Reference==
@@ Line 20: / Line 20: @@
 [[Category: unsaturated glucuronyl hydrolase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 09:27:14 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:55:36 2008''