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Glycoside Hydrolase Family 77

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Glycoside Hydrolase Family GH77
Clan GH-H
Mechanism retaining
Active site residues known
CAZy DB link

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, 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

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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
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  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 | PubMed ID:18838391 [Cantarel2009]
  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 | PubMed ID:11257505 [MacGregor2001]
  3. Takaha T, Yanase M, Okada S, and Smith SM. (1993). Disproportionating enzyme (4-alpha-glucanotransferase; EC of potato. Purification, molecular cloning, and potential role in starch metabolism. J Biol Chem. 1993;268(2):1391-6. | Google Books | Open Library PubMed ID:7678257 [Takaha1993]
  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 | PubMed ID:10049841 [Terada1999]
  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 | PubMed ID:16151092 [Kaper2005]
  6. Leemhuis H, Kelly RM, and Dijkhuizen L. (2010). Engineering of cyclodextrin glucanotransferases and the impact for biotechnological applications. Appl Microbiol Biotechnol. 2010;85(4):823-35. DOI:10.1007/s00253-009-2221-3 | PubMed ID:19763564 [Leemhuis2010]
  7. Godány A, Vidová B, and Janecek S. (2008). The unique glycoside hydrolase family 77 amylomaltase from Borrelia burgdorferi with only catalytic triad conserved. FEMS Microbiol Lett. 2008;284(1):84-91. DOI:10.1111/j.1574-6968.2008.01191.x | PubMed ID:18494783 [Godany2008]
  8. Przylas I, Tomoo K, Terada Y, Takaha T, Fujii K, Saenger W, and Sträter N. (2000). Crystal structure of amylomaltase from thermus aquaticus, a glycosyltransferase catalysing the production of large cyclic glucans. J Mol Biol. 2000;296(3):873-86. DOI:10.1006/jmbi.1999.3503 | PubMed ID:10677288 [Przylas2000]
  9. Przylas I, Terada Y, Fujii K, Takaha T, Saenger W, and Sträter N. (2000). X-ray structure of acarbose bound to amylomaltase from Thermus aquaticus. Implications for the synthesis of large cyclic glucans. Eur J Biochem. 2000;267(23):6903-13. DOI:10.1046/j.1432-1033.2000.01790.x | PubMed ID:11082203 [Przylas2000]
  10. Srisimarat W, Murakami S, Pongsawasdi P, and Krusong K. (2013). Crystallization and preliminary X-ray crystallographic analysis of the amylomaltase from Corynebacterium glutamicum. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013;69(Pt 9):1004-6. DOI:10.1107/S1744309113020319 | PubMed ID:23989149 [Srisimarat2013]
  11. Hoon-Hanks LL, Morton EA, Lybecker MC, Battisti JM, Samuels DS, and Drecktrah D. (2012). Borrelia burgdorferi malQ mutants utilize disaccharides and traverse the enzootic cycle. FEMS Immunol Med Microbiol. 2012;66(2):157-65. DOI:10.1111/j.1574-695X.2012.00996.x | PubMed ID:22672337 [Hoon-Hanks2012]
  12. Jung JH, Jung TY, Seo DH, Yoon SM, Choi HC, Park BC, Park CS, and Woo EJ. (2011). Structural and functional analysis of substrate recognition by the 250s loop in amylomaltase from Thermus brockianus. Proteins. 2011;79(2):633-44. DOI:10.1002/prot.22911 | PubMed ID:21117235 [Jung2011]
  13. van der Maarel MJ and Leemhuis H. (2013). Starch modification with microbial alpha-glucanotransferase enzymes. Carbohydr Polym. 2013;93(1):116-21. DOI:10.1016/j.carbpol.2012.01.065 | PubMed ID:23465909 [vanderMaarel2013]

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