Glycoside Hydrolase Family 77

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• Author: ^^^Stefan Janecek^^^
• Responsible Curator: ^^^Stefan Janecek^^^

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Glycoside Hydrolase Family GH77
Clan	GH-H
Mechanism	retaining
Active site residues	known
CAZy DB link
http://www.cazy.org/fam/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 April 2010, it has more than 700 members [1] with more than 650 from Bacteria, ~10 from Archaea and a few tens from 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 [3, 4, 5]. Cyclodextrin glucanotransferase, a member of the α-amylase family GH13, also produces cyclic α- 1,4-glucans (called cyclodextrins), but with a small degree of polymerization (from 6-8 referred to as α-, Normal 0 21 false false false SK X-NONE X-NONE MicrosoftInternetExplorer4 β- and γ-cyclodextrins

Catalytic Residues

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Three-dimensional structures

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Family Firsts

First stereochemistry determination

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First catalytic nucleophile identification

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First general acid/base residue identification

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First 3-D structure

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References

1. Cantarel BL, Coutinho PM, Rancurel C, Bernard T, Lombard V, and Henrissat B. (2009). The Carbohydrate-Active EnZymes database (CAZy): an expert resource for Glycogenomics. Nucleic Acids Res. 2009;37(Database issue):D233-8. DOI:10.1093/nar/gkn663 |
2. MacGregor EA, Janecek S, and Svensson B. (2001). Relationship of sequence and structure to specificity in the alpha-amylase family of enzymes. Biochim Biophys Acta. 2001;1546(1):1-20. DOI:10.1016/s0167-4838(00)00302-2 |
3. Takaha T, Yanase M, Okada S, and Smith SM. (1993). Disproportionating enzyme (4-alpha-glucanotransferase; EC 2.4.1.25) of potato. Purification, molecular cloning, and potential role in starch metabolism. J Biol Chem. 1993;268(2):1391-6. | Google Books | Open Library
4. Terada Y, Fujii K, Takaha T, and Okada S. (1999). Thermus aquaticus ATCC 33923 amylomaltase gene cloning and expression and enzyme characterization: production of cycloamylose. Appl Environ Microbiol. 1999;65(3):910-5. DOI:10.1128/AEM.65.3.910-915.1999 |
5. Kaper T, Talik B, Ettema TJ, Bos H, van der Maarel MJ, and Dijkhuizen L. (2005). Amylomaltase of Pyrobaculum aerophilum IM2 produces thermoreversible starch gels. Appl Environ Microbiol. 2005;71(9):5098-106. DOI:10.1128/AEM.71.9.5098-5106.2005 |