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Difference between revisions of "Glycoside Hydrolase Family 128"
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== Substrate specificities == | == Substrate specificities == | ||
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Family GH128 contains β-1,3-glucanases that cleave β-1,3 linkages in various β-glucans such as lentinan from ''Lentinula edodes'', laminarin from ''Laminaria digitata'', pachyman from ''Poria cocos'' and curdlan from ''Alcaligenes faecalis''. The first GH128 enzyme, GLU1, was cloned from ''L. edodes'' fruiting bodies (shiitake mushroom). GLU1 did not degrade β-1,3-linkages within β-1,3-1,4-glucans such as barley glucan, indicating the enzyme is categorized into (EC [{{EClink}}3.2.1.39 3.2.1.39]) <cite>Sakamoto2011</cite>. | Family GH128 contains β-1,3-glucanases that cleave β-1,3 linkages in various β-glucans such as lentinan from ''Lentinula edodes'', laminarin from ''Laminaria digitata'', pachyman from ''Poria cocos'' and curdlan from ''Alcaligenes faecalis''. The first GH128 enzyme, GLU1, was cloned from ''L. edodes'' fruiting bodies (shiitake mushroom). GLU1 did not degrade β-1,3-linkages within β-1,3-1,4-glucans such as barley glucan, indicating the enzyme is categorized into (EC [{{EClink}}3.2.1.39 3.2.1.39]) <cite>Sakamoto2011</cite>. | ||
== Kinetics and Mechanism == | == Kinetics and Mechanism == | ||
| − | + | A GH128 enzyme, GLU1, catalyzed depolymerization of glucans composed of b-1,3-linked main chains, and reaction product analysis indicated that the enzyme had an endolytic mode. The optimal pH and temperature of the enzyme for laminarin were pH 4 and at 50 °C, respectively. From the result of the three-dimensional structure prediction, GLU1 would be categorized to GH-A clan in CAZy server. Therefore, it have been inferred that GH 128 enzymes are retaining enzymes <cite>Sakamoto2011</cite>. | |
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| − | A GH128 enzyme, GLU1, catalyzed depolymerization of glucans composed of b-1,3-linked main chains, and reaction product analysis indicated that the enzyme had an endolytic mode. The optimal pH and temperature of the enzyme for laminarin were pH 4 and at 50 °C, respectively. From the result of the three-dimensional structure prediction, GLU1 would be categorized to GH-A clan in CAZy server. Therefore, it have been inferred that GH 128 enzymes are retaining enzymes | ||
== Catalytic Residues == | == Catalytic Residues == | ||
| − | + | From the sequence alignment of GH128 members, two conserved glutamic acids, E103 and E195 in GLU1, were expected to perform as the catalytic residues | |
== Three-dimensional structures == | == Three-dimensional structures == | ||
| − | + | The deduced sequence of GLU1 was used to predict three-dimensional structure using the Phyre server (http://www.sbg.bio.ic.ac.uk/~phyre/; 9). The result indicated that the three-dimensional structure of GLU1 matches some (b/a)8 TIM barrel structures, such as GH39 b-xylosidase (Q9ZFM2) and GH5 b-mannanase (Q4W8M3). Therefore, GH128 would be categorized to GH-A clan <cite>Sakamoto2011</cite>. | |
== Family Firsts == | == Family Firsts == | ||
Revision as of 15:56, 22 July 2015
This page is currently under construction. This means that the Responsible Curator has deemed that the page's content is not quite up to CAZypedia's standards for full public consumption. All information should be considered to be under revision and may be subject to major changes.
- Author: ^^^Yuichi Sakamoto^^^
- Responsible Curator: ^^^Yuichi Sakamoto^^^
| Glycoside Hydrolase Family GH128 | |
| Clan | GH-x |
| Mechanism | retaining/inverting |
| Active site residues | known/not known |
| CAZy DB link | |
| https://www.cazy.org/GH128.html | |
Substrate specificities
Family GH128 contains β-1,3-glucanases that cleave β-1,3 linkages in various β-glucans such as lentinan from Lentinula edodes, laminarin from Laminaria digitata, pachyman from Poria cocos and curdlan from Alcaligenes faecalis. The first GH128 enzyme, GLU1, was cloned from L. edodes fruiting bodies (shiitake mushroom). GLU1 did not degrade β-1,3-linkages within β-1,3-1,4-glucans such as barley glucan, indicating the enzyme is categorized into (EC 3.2.1.39) [1].
Kinetics and Mechanism
A GH128 enzyme, GLU1, catalyzed depolymerization of glucans composed of b-1,3-linked main chains, and reaction product analysis indicated that the enzyme had an endolytic mode. The optimal pH and temperature of the enzyme for laminarin were pH 4 and at 50 °C, respectively. From the result of the three-dimensional structure prediction, GLU1 would be categorized to GH-A clan in CAZy server. Therefore, it have been inferred that GH 128 enzymes are retaining enzymes [1].
Catalytic Residues
From the sequence alignment of GH128 members, two conserved glutamic acids, E103 and E195 in GLU1, were expected to perform as the catalytic residues
Three-dimensional structures
The deduced sequence of GLU1 was used to predict three-dimensional structure using the Phyre server (http://www.sbg.bio.ic.ac.uk/~phyre/; 9). The result indicated that the three-dimensional structure of GLU1 matches some (b/a)8 TIM barrel structures, such as GH39 b-xylosidase (Q9ZFM2) and GH5 b-mannanase (Q4W8M3). Therefore, GH128 would be categorized to GH-A clan [1].
Family Firsts
- First stereochemistry determination
- Content is to be added here.
- First catalytic nucleophile identification
- Content is to be added here.
- First general acid/base residue identification
- Content is to be added here.
- First 3-D structure
- Content is to be added here.