New to the CAZy classification? Read this first.
Glycoside Hydrolase Family 57
Responsible Curator as essentially complete. CAZypedia is a living document, so further improvement of this page is still possible. If you would like to suggest an addition or correction, please contact the page's Responsible Curator directly by e-mail, or using this form.
|Glycoside Hydrolase Family GH57|
|Clan||not assigned yet|
|Active site residues||known|
|CAZy DB link|
Glycoside hydrolase family 57 was established in 1996  based on the existence of the sequences of two “α-amylases” that were dissimilar to typical family GH13 α-amylases . The two were the heat-stable eubacterial amylase from Dictyoglomus thermophilum known from 1988  and the extremely thermostable archaeal amylase from Pyrococcus furiosus determined in 1993 .
The family has expanded mainly due to the results of genome sequencing projects. More than a thousand of members are known [5, 6], all from prokaryotes (with ~1:4 ratio for Archaea:Bacteria) . The enzyme specificities of family GH57 includes α-amylase (EC 22.214.171.124), α-galactosidase (EC 126.96.36.199), amylopullulanase (EC 188.8.131.52), branching enzyme (EC 184.108.40.206) and 4-α-glucanotransferase (EC 220.127.116.11).
An archaeal GH57 amylopullulanase from Staphylothermus marinus has been described exhibiting also the activity of cyclodextrinase (EC 18.104.22.168) . Based on a preliminary observation that the PF0870 protein encoded in the Pyrococcus furiosus genome produced maltose , a group of GH57 members with proposed specificity of maltogenic amylase (EC 22.214.171.124) was predicted  together with another group of non-specified amylases following the partial characterization of an amylolytic enzyme from an uncultured bacterium . The maltogenic specificity (or maltose-forming amylase) has already been definitively confirmed by both biochemical [12, 13] and structural  studies. The family GH57 contains further a group of probably non-enzymatic members, i.e. the so-called α-amylase-like proteins having a substitution in one or both catalytic residues .
It is worth mentioning that the two founding members, i.e. the “α-amylases” from Dictyoglomus thermophilum and Pyrococcus furiosus are 4-α-glucanotransferases; the former was proven to have transglycosylating activity , whereas the latter was already known to exhibit also the 4-α-glucanotransferase activity .
A detailed in silico study has indicated a close relatedness of family GH57 to the family GH119 concerning catalytic domain fold, catalytic machinery and conserved sequence regions .
Kinetics and Mechanism
A direct evidence for the stereochemical outcome of the enzyme-catalyzed reaction has been presented for the branching enzyme from Thermus thermophilus  by the NMR analysis of reaction products. The previous observation of a trapped covalent glycosyl-enzyme intermediate  was also a strong evidence that the GH57 enzymes operate with retention of anomeric configuration through a classical Koshland retaining mechanism with retention of anomeric configuration. The X-ray structure of the 4-α-glucanotransferase from Thermococcus litoralis revealed average distances of 6.72 Å and 6.97 Å between the catalytic nucleophile (Glu123) and general acid/base (Asp214) in the free and acarbose-bound forms of the enzyme, respectively, which also supports a retaining mechanism for this family  (see also ).
Detailed kinetic studies have been performed on several GH57 enzymes, including the 4-α-glucanotransferases from Thermococcus litoralis [20, 21] and Pyrococcus furiosus , amylopullulanases from Thermococcus hydrothermalis  and Pyrococcus furiosus , and branching enzymes from Thermococcus kodakaraensis  and Thermus thermophilus .
The sequences of GH57 members are very diverse. Some sequences are shorter than 400 residues whereas others are longer than 1,500 residues . This complicated early efforts to align the GH57 sequences using standard alignment methods. A detailed bioinformatics study by Zona et al.  focused on all available GH57 sequences at that time and identified five conserved sequence regions. This study used knowledge of the identity of the catalytic nucleophile (Glu123) in the GH57 4-α-glucanotransferase from Thermococcus litoralis  together with the three-dimensional structure  (PDB ID 1k1w) that revealed the general acid/base residue (Asp214).
The catalytic nucleophile (a glutamate) and general acid/base (an aspartate) are located in the conserved sequence regions 3 and 4, respectively. In addition to assignments in Thermococcus litoralis 4-α-glucanotransferase discussed above, these residues were identified in the amylopullulanases from Thermococcus hydrothermalis  and Pyrococcus furiosus . The catalytic nucleophile was also identified in the α-galactosidase from Pyrococcus furiosus although no success was achieved in assigning the general acid/base . It should be taken into account that some GH57 members, which are only hypothetical enzymes/proteins without any biochemical characterization, may lack one or even both catalytic residues [15, 24].
Based on the five identified conserved sequence regions, the residues His13, Glu79, Glu216 and Asp354 together with Trp120, Trp221 and Trp357 (Thermococcus hydrothermalis amylopullulanase numbering) were postulated  as important determinants of the individual GH57 enzyme specificities [7, 10, 15]. Of these, the Trp221 has already been confirmed to contribute to the transglycosylation activity of 4-α-glucanotransferase since the mutant W229H of the enzyme from Pyrococcus furiosus exhibited markedly decreased transglycosylation activity in comparison with the wild-type counterpart .
The structure of the catalytic domain adopts a (β/α)7-barrel, i.e. the irregular (β/α)8-barrel called a pseudo TIM-barrel. In the case of the Thermococcus litoralis 4-α-glucanotransferase  the catalytic domain is succeeded by a C-terminal non-catalytic domain consisting of only β-strands that adopts a twisted β-sandwich fold. In the three-dimensional structure of the α-amylase AmyC from Thermotoga maritima  (PDB ID 2b5d) (note that the sequence of this enzyme strongly resemles that of a branching enzyme ), the corresponding catalytic (β/α)7-barrel is followed by a five-helix domain C, a small helical domain B being protruded out of the catalytic pseudo TIM barrel in the place of the loop 2 (i.e. succeeding the strand β2). This structure was found to be closely similar to that of the GH57 member of unknown function from Thermus thermophilus (PDB ID 1ufa). Two structures of biochemically characterized branching enzymes were solved and published: one from Thermus thermophilus  (PDB ID 3p0b) and the other one from Thermococcus kodakaraensis  (PDB ID 3n8t). The former study , importantly, is the first report to prove that a retaining mechanism is employed in the family GH57. Also, the 3-D structure is available for the maltogenic (maltose-forming) amylase from Pyrococcus sp. ST04  (PDB ID 4cmr). In all cases, the catalytic glutamic acid and aspartic acid residues are located near the C-terminal ends of the strands β4 and β7 of the barrel, respectively [21, 29]. There was also a crystallization report in 1995 on a probable GH57 amylopullulanase from Pyrococcus woesei , but the detailed crystallographic analysis of this protein has not been published.
It is clear that the C-terminal domain cannot be present in some GH57 members with shorter amino acid sequences, e.g., in the α-galactosidases containing less than 400 residues . On the other hand, some other GH57 members, especially the extra-long amylopullulanases with more than 1,300 residues  have to contain even additional domains. One of them could be a longer version of a typical surface layer homology (SLH) motif  that was named as the so-called SLH motif-bearing domain in the amylopullulanase from Thermococcus hydrothermalis . This domain was found also in the GH15 glucodextranase from Arthrobacter globiformis . Remarkably, within the family GH57, the presence of this SLH motif-bearing domain is restricted only for amylopullulanases .
It is also worth mentioning that, especially prior the first three-dimensional structure of a GH57 member was available, there were some efforts to join the family GH57 with the main α-amylase family GH13, i.e. the present clan [GH-H] consisting of the families GH13, GH70 and GH77 . Those efforts were focused mainly on looking for some remote homology at the sequence level only [36, 37]. Although both GH57 and GH-H employ the same retaining reaction mechanism [21, 38] the independence of the family GH57 with regard to GH-H clan is at present based not only on differences in the catalytic domain, but more importantly, on the differences in the catalytic machineries and conserved sequence regions [24, 39]. As far as other GH families are concerned, the family GH38 α-mannosidase from Drosophila melanogaster  was revealed to share some structural similarities within the catalytic domain with the GH57 4-α-glucanotransferase from Thermococcus litoralis [20, 21] indicating an eventuality of originating from a common ancestor.
- First sterochemistry determination
- The first direct evidence of the retaining reaction stereochemistry by product analysis has been delivered by 1H-NMR analysis of the product mixture that confirmed the α-anomeric configuration of the α-1,6-glucosidic bond formed after the incubation of Thermus thermophilus branching enzyme with amylose . Previously, family GH57 enzymes have been indicated to be retaining by trapping of a covalent glycosyl-enzyme intermediate  and a 6.7 Å distance between the catalytic nucleophile and acid/base , both of which are consistent with a two-step, double-displacement mechanism.
- First amino acid sequence determination
- The first amino acid sequence of the family GH57 was that of the heat stable amylase from an anaerobic thermophilic bacterium Dictyoglomus thermophilum . This "α-amylase" was later characterized as 4-α-glucanotransferase . In fact, the family contains many α-amylase-like proteins, i.e. those that exhibit a clear sequence homology with α-amylases, but possess a substitution in one or both catalytic residues .
- First conserved sequence regions determination
- The five sequence stretches characteristic as conserved regions for the family GH57 were first determined by the bioinformatics study by Zona et al. (2004) .
- First catalytic nucleophile identification
- The catalytic nucleophile was fist identified by Imamura et al. (2001)  as Glu123 in the 4-α-glucanotransferase from Thermococcus litoralis using the 3-ketobutylidene-β-2-chloro-4-nitrophenyl maltopentaoside as a donor.
- First general acid/base residue identification
- Asp214 of the 4-α-glucanotransferase from Thermococcus litoralis as indicated by the X-ray crystallography and supported by site-directed mutagenesis  since the D214N mutant exhibited a 10,000-fold decrease of specific activity in comparison with the wild-type enzyme.
- First 3-D structure
- The first 3-D structure of a GH57 member was that of the 4-α-glucanotransferase from Thermococcus litoralis .
- Henrissat B and Bairoch A. Updating the sequence-based classification of glycosyl hydrolases. Biochem J. 1996 Jun 1;316 ( Pt 2):695-6.
- MacGregor EA, Janecek S, and Svensson B. Relationship of sequence and structure to specificity in the alpha-amylase family of enzymes. Biochim Biophys Acta. 2001 Mar 9;1546(1):1-20.
- Fukusumi S, Kamizono A, Horinouchi S, and Beppu T. Cloning and nucleotide sequence of a heat-stable amylase gene from an anaerobic thermophile, Dictyoglomus thermophilum. Eur J Biochem. 1988 May 16;174(1):15-21.
- Laderman KA, Asada K, Uemori T, Mukai H, Taguchi Y, Kato I, and Anfinsen CB. Alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus. Cloning and sequencing of the gene and expression in Escherichia coli. J Biol Chem. 1993 Nov 15;268(32):24402-7.
- Cantarel BL, Coutinho PM, Rancurel C, Bernard T, Lombard V, and Henrissat B. The Carbohydrate-Active EnZymes database (CAZy): an expert resource for Glycogenomics. Nucleic Acids Res. 2009 Jan;37(Database issue):D233-8. DOI:10.1093/nar/gkn663 |
- Lombard V, Golaconda Ramulu H, Drula E, Coutinho PM, and Henrissat B. The carbohydrate-active enzymes database (CAZy) in 2013. Nucleic Acids Res. 2014 Jan;42(Database issue):D490-5. DOI:10.1093/nar/gkt1178 |
- Blesák K and Janeček S. Sequence fingerprints of enzyme specificities from the glycoside hydrolase family GH57. Extremophiles. 2012 May;16(3):497-506. DOI:10.1007/s00792-012-0449-9 |
- Li X, Li D, and Park KH. An extremely thermostable amylopullulanase from Staphylothermus marinus displays both pullulan- and cyclodextrin-degrading activities. Appl Microbiol Biotechnol. 2013 Jun;97(12):5359-69. DOI:10.1007/s00253-012-4397-1 |
- Comfort DA, Chou CJ, Conners SB, VanFossen AL, and Kelly RM. Functional-genomics-based identification and characterization of open reading frames encoding alpha-glucoside-processing enzymes in the hyperthermophilic archaeon Pyrococcus furiosus. Appl Environ Microbiol. 2008 Feb;74(4):1281-3. DOI:10.1128/AEM.01920-07 |
- Blesák K and Janeček Š. Two potentially novel amylolytic enzyme specificities in the prokaryotic glycoside hydrolase α-amylase family GH57. Microbiology. 2013 Dec;159(Pt 12):2584-93. DOI:10.1099/mic.0.071084-0 |
- Wang H, Gong Y, Xie W, Xiao W, Wang J, Zheng Y, Hu J, and Liu Z. Identification and characterization of a novel thermostable gh-57 gene from metagenomic fosmid library of the Juan de Fuca Ridge hydrothemal vent. Appl Biochem Biotechnol. 2011 Aug;164(8):1323-38. DOI:10.1007/s12010-011-9215-1 |
- Jung JH, Seo DH, Holden JF, and Park CS. Maltose-forming α-amylase from the hyperthermophilic archaeon Pyrococcus sp. ST04. Appl Microbiol Biotechnol. 2014 Mar;98(5):2121-31. DOI:10.1007/s00253-013-5068-6 |
- Jeon EJ, Jung JH, Seo DH, Jung DH, Holden JF, and Park CS. Bioinformatic and biochemical analysis of a novel maltose-forming α-amylase of the GH57 family in the hyperthermophilic archaeon Thermococcus sp. CL1. Enzyme Microb Technol. 2014 Jun 10;60:9-15. DOI:10.1016/j.enzmictec.2014.03.009 |
- Park KH, Jung JH, Park SG, Lee ME, Holden JF, Park CS, and Woo EJ. Structural features underlying the selective cleavage of a novel exo-type maltose-forming amylase from Pyrococcus sp. ST04. Acta Crystallogr D Biol Crystallogr. 2014 Jun;70(Pt 6):1659-68. DOI:10.1107/S1399004714006567 |
- Janeček S and Blesák K. Sequence-structural features and evolutionary relationships of family GH57 α-amylases and their putative α-amylase-like homologues. Protein J. 2011 Aug;30(6):429-35. DOI:10.1007/s10930-011-9348-7 |
- Nakajima M, Imamura H, Shoun H, Horinouchi S, and Wakagi T. Transglycosylation activity of Dictyoglomus thermophilum amylase A. Biosci Biotechnol Biochem. 2004 Nov;68(11):2369-73. DOI:10.1271/bbb.68.2369 |
- Laderman KA, Davis BR, Krutzsch HC, Lewis MS, Griko YV, Privalov PL, and Anfinsen CB. The purification and characterization of an extremely thermostable alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus. J Biol Chem. 1993 Nov 15;268(32):24394-401.
- Janeček S and Kuchtová A. In silico identification of catalytic residues and domain fold of the family GH119 sharing the catalytic machinery with the α-amylase family GH57. FEBS Lett. 2012 Sep 21;586(19):3360-6. DOI:10.1016/j.febslet.2012.07.020 |
- Palomo M, Pijning T, Booiman T, Dobruchowska JM, van der Vlist J, Kralj S, Planas A, Loos K, Kamerling JP, Dijkstra BW, van der Maarel MJ, Dijkhuizen L, and Leemhuis H. Thermus thermophilus glycoside hydrolase family 57 branching enzyme: crystal structure, mechanism of action, and products formed. J Biol Chem. 2011 Feb 4;286(5):3520-30. DOI:10.1074/jbc.M110.179515 |
- Imamura H, Fushinobu S, Jeon BS, Wakagi T, and Matsuzawa H. Identification of the catalytic residue of Thermococcus litoralis 4-alpha-glucanotransferase through mechanism-based labeling. Biochemistry. 2001 Oct 16;40(41):12400-6.
- Imamura H, Fushinobu S, Yamamoto M, Kumasaka T, Jeon BS, Wakagi T, and Matsuzawa H. Crystal structures of 4-alpha-glucanotransferase from Thermococcus litoralis and its complex with an inhibitor. J Biol Chem. 2003 May 23;278(21):19378-86. DOI:10.1074/jbc.M213134200 |
- Davies G and Henrissat B. Structures and mechanisms of glycosyl hydrolases. Structure. 1995 Sep 15;3(9):853-9. DOI:10.1016/S0969-2126(01)00220-9 |
- Tang SY, Yang SJ, Cha H, Woo EJ, Park C, and Park KH. Contribution of W229 to the transglycosylation activity of 4-alpha-glucanotransferase from Pyrococcus furiosus. Biochim Biophys Acta. 2006 Oct;1764(10):1633-8. DOI:10.1016/j.bbapap.2006.08.013 |
- Zona R, Chang-Pi-Hin F, O'Donohue MJ, and Janecek S. Bioinformatics of the glycoside hydrolase family 57 and identification of catalytic residues in amylopullulanase from Thermococcus hydrothermalis. Eur J Biochem. 2004 Jul;271(14):2863-72. DOI:10.1111/j.1432-1033.2004.04144.x |
- Kang S, Vieille C, and Zeikus JG. Identification of Pyrococcus furiosus amylopullulanase catalytic residues. Appl Microbiol Biotechnol. 2005 Jan;66(4):408-13. DOI:10.1007/s00253-004-1690-7 |
- Murakami T, Kanai T, Takata H, Kuriki T, and Imanaka T. A novel branching enzyme of the GH-57 family in the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. J Bacteriol. 2006 Aug;188(16):5915-24. DOI:10.1128/JB.00390-06 |
- Janecek S Amylolytic families of glycoside hydrolases: focus on the family GH-57. Biologia 2005; 60(Suppl. 16) 177-84. (PDF)
- van Lieshout JFT, Verhees CH, Ettema TJG, van der Saar S, Imamura H, Matsuzawa H, van der Oost J, de Vos WM. Identification and molecular characterization of a novel type of α-galactosidase from Pyrococcus furiosus. Biocatal Biotransform 2003; 21(4-5) 243-52. (DOI: 10.1080/10242420310001614342)
- Dickmanns A, Ballschmiter M, Liebl W, and Ficner R. Structure of the novel alpha-amylase AmyC from Thermotoga maritima. Acta Crystallogr D Biol Crystallogr. 2006 Mar;62(Pt 3):262-70. DOI:10.1107/S0907444905041363 |
- Santos CR, Tonoli CC, Trindade DM, Betzel C, Takata H, Kuriki T, Kanai T, Imanaka T, Arni RK, and Murakami MT. Structural basis for branching-enzyme activity of glycoside hydrolase family 57: structure and stability studies of a novel branching enzyme from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. Proteins. 2011 Feb;79(2):547-57. DOI:10.1002/prot.22902 |
- Knapp S, Rüdiger A, Antranikian G, Jorgensen PL, and Ladenstein R. Crystallization and preliminary crystallographic analysis of an amylopullulanase from the hyperthermophilic archaeon Pyrococcus woesei. Proteins. 1995 Dec;23(4):595-7. DOI:10.1002/prot.340230416 |
- Erra-Pujada M, Debeire P, Duchiron F, and O'Donohue MJ. The type II pullulanase of Thermococcus hydrothermalis: molecular characterization of the gene and expression of the catalytic domain. J Bacteriol. 1999 May;181(10):3284-7.
- Lupas A, Engelhardt H, Peters J, Santarius U, Volker S, and Baumeister W. Domain structure of the Acetogenium kivui surface layer revealed by electron crystallography and sequence analysis. J Bacteriol. 1994 Mar;176(5):1224-33.
- Mizuno M, Tonozuka T, Suzuki S, Uotsu-Tomita R, Kamitori S, Nishikawa A, and Sakano Y. Structural insights into substrate specificity and function of glucodextranase. J Biol Chem. 2004 Mar 12;279(11):10575-83. DOI:10.1074/jbc.M310771200 |
- Zona R, Janecek S. Relationships between SLH motifs from different glycoside hydrolase families. Biologia 2005; 60(Suppl. 16): 115-21. (PDF)
- Dong G, Vieille C, and Zeikus JG. Cloning, sequencing, and expression of the gene encoding amylopullulanase from Pyrococcus furiosus and biochemical characterization of the recombinant enzyme. Appl Environ Microbiol. 1997 Sep;63(9):3577-84.
- Janecek S. Sequence of archaeal Methanococcus jannaschii alpha-amylase contains features of families 13 and 57 of glycosyl hydrolases: a trace of their common ancestor?. Folia Microbiol (Praha). 1998;43(2):123-8.
- Matsuura Y, Kusunoki M, Harada W, and Kakudo M. Structure and possible catalytic residues of Taka-amylase A. J Biochem. 1984 Mar;95(3):697-702.
- Janecek S. How many conserved sequence regions are there in the α-amylase family? Biologia 2002; 57(Suppl. 11): 29-41. (PDF)
- van den Elsen JM, Kuntz DA, and Rose DR. Structure of Golgi alpha-mannosidase II: a target for inhibition of growth and metastasis of cancer cells. EMBO J. 2001 Jun 15;20(12):3008-17. DOI:10.1093/emboj/20.12.3008 |