Difference between revisions of "Glycoside Hydrolase Family 77"

Revision as of 06:06, 30 June 2014

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: ^^^Stefan Janecek^^^
Responsible Curator: ^^^Stefan Janecek^^^

Glycoside Hydrolase Family GH77
Clan	GH-H
Mechanism	retaining
Active site residues	known
CAZy DB link
https://www.cazy.org/GH77.html

Substrate specificities

Glycoside hydrolase family 77 is the member of the α-amylase clan GH-H [1], together with GH13 and GH70 [2]. The family contains only one enzyme specificity - the amylomaltase (EC 2.4.1.25), that is known as disproportionating enzyme (D-enzyme) in plants [3] or 4-α-glucanotransferase in bacteria [4] and archaeons [5]. As of June 2014, it has more than 2,000 members [1] with ~1,950 from Bacteria, and about 30 from each Archaea and Eukarya (plants and green algae).

Amylomaltase catalyses the glucan-chain transfer from one α-1,4-glucan to another α-1,4-glucan (or to 4-hydroxyl group of glucose) or within a single linear glucan molecule to produce a cyclic α-1,4-glucan with degree of polymerization starting from 17 [3, 4, 5]. Cyclodextrin glucanotransferase, a member of the α-amylase family GH13, also produces cyclic α-1,4-glucans, but with a small degree of polymerization (6-8), called cyclodextrins [6].

Kinetics and Mechanism

Catalytic Residues

Content is to be added here.

Three-dimensional structures

Content is to be added here.

Family Firsts

First stereochemistry determination: Cite some reference here, with a short (1-2 sentence) explanation.
First catalytic nucleophile identification: Cite some reference here, with a short (1-2 sentence) explanation.
First general acid/base residue identification: Cite some reference here, with a short (1-2 sentence) explanation.
First 3-D structure: Cite some reference here, with a short (1-2 sentence) explanation.

References

All Medline abstracts: PubMed

@@ Line 29: / Line 29: @@
 == Substrate specificities ==
-[[Glycoside hydrolase]] family 77 is the member of the α-amylase [[clans|clan]] [[GH-H]] <cite>Cantarel2009</cite>, together with [[GH13]] and [[GH70]] <cite>MacGregor2001</cite>. The family contains only one enzyme specificity - the amylomaltase (EC [{{EClink}}2.4.1.25 2.4.1.25]), that is known as disproportionating enzyme (D-enzyme) in plants <cite>Takaha1993</cite> or 4-α-glucanotransferase in bacteria <cite>Terada1999</cite> and archaeons <cite>Kaper2005</cite>. As of April 2010, it has more than 700 members <cite>Cantarel2009</cite> with more than 650 from Bacteria, ~10 from Archaea and a few tens from Eukarya (plants and green algae).
+[[Glycoside hydrolase]] family 77 is the member of the α-amylase [[clans|clan]] [[GH-H]] <cite>Cantarel2009</cite>, together with [[GH13]] and [[GH70]] <cite>MacGregor2001</cite>. The family contains only one enzyme specificity - the amylomaltase (EC [{{EClink}}2.4.1.25 2.4.1.25]), that is known as disproportionating enzyme (D-enzyme) in plants <cite>Takaha1993</cite> or 4-α-glucanotransferase in bacteria <cite>Terada1999</cite> and archaeons <cite>Kaper2005</cite>. As of June 2014, it has more than 2,000 members <cite>Cantarel2009</cite> with ~1,950 from Bacteria, and about 30 from each Archaea and Eukarya (plants and green algae).
 Amylomaltase catalyses the glucan-chain transfer from one α-1,4-glucan to another α-1,4-glucan (or to 4-hydroxyl group of glucose) or within a single linear glucan molecule to produce a cyclic α-1,4-glucan with degree of polymerization starting from 17 <cite>Takaha1993,Terada1999,Kaper2005</cite>. Cyclodextrin glucanotransferase, a member of the α-amylase family [[GH13]], also produces cyclic α-1,4-glucans, but with a small degree of polymerization (6-8), called cyclodextrins <cite>Leemhuis2010</cite>.