alpha-amylase family protein may catalyze the hydrolysis of alpha-(1,4) glycosidic linkages of glycogen, starch, related polysaccharides, and some oligosaccharides
Alpha amylase catalytic domain family; The Alpha-amylase family comprises the largest family ...
25-383
4.69e-144
Alpha amylase catalytic domain family; The Alpha-amylase family comprises the largest family of glycoside hydrolases (GH), with the majority of enzymes acting on starch, glycogen, and related oligo- and polysaccharides. These proteins catalyze the transformation of alpha-1,4 and alpha-1,6 glucosidic linkages with retention of the anomeric center. The protein is described as having 3 domains: A, B, C. A is a (beta/alpha) 8-barrel; B is a loop between the beta 3 strand and alpha 3 helix of A; and C is the C-terminal extension characterized by a Greek key. The majority of the enzymes have an active site cleft found between domains A and B where a triad of catalytic residues (Asp, Glu and Asp) performs catalysis. Other members of this family have lost this catalytic activity as in the case of the human 4F2hc, or only have 2 residues that serve as the catalytic nucleophile and the acid/base, such as Thermus A4 beta-galactosidase with 2 Glu residues (GH42) and human alpha-galactosidase with 2 Asp residues (GH31). The family members are quite extensive and include: alpha amylase, maltosyltransferase, cyclodextrin glycotransferase, maltogenic amylase, neopullulanase, isoamylase, 1,4-alpha-D-glucan maltotetrahydrolase, 4-alpha-glucotransferase, oligo-1,6-glucosidase, amylosucrase, sucrose phosphorylase, and amylomaltase.
The actual alignment was detected with superfamily member PLN02808:
Pssm-ID: 476817 [Multi-domain] Cd Length: 386 Bit Score: 415.90 E-value: 4.69e-144
glycosyl hydrolase family 27 (GH27); GH27 enzymes occur in eukaryotes, prokaryotes, and ...
35-296
4.77e-144
glycosyl hydrolase family 27 (GH27); GH27 enzymes occur in eukaryotes, prokaryotes, and archaea with a wide range of hydrolytic activities, including alpha-glucosidase (glucoamylase and sucrase-isomaltase), alpha-N-acetylgalactosaminidase, and 3-alpha-isomalto-dextranase. All GH27 enzymes cleave a terminal carbohydrate moiety from a substrate that varies considerably in size, depending on the enzyme, and may be either a starch or a glycoprotein. GH27 members are retaining enzymes that cleave their substrates via an acid/base-catalyzed, double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively.
Pssm-ID: 269893 [Multi-domain] Cd Length: 271 Bit Score: 411.18 E-value: 4.77e-144
glycosyl hydrolase family 27 (GH27); GH27 enzymes occur in eukaryotes, prokaryotes, and ...
35-296
4.77e-144
glycosyl hydrolase family 27 (GH27); GH27 enzymes occur in eukaryotes, prokaryotes, and archaea with a wide range of hydrolytic activities, including alpha-glucosidase (glucoamylase and sucrase-isomaltase), alpha-N-acetylgalactosaminidase, and 3-alpha-isomalto-dextranase. All GH27 enzymes cleave a terminal carbohydrate moiety from a substrate that varies considerably in size, depending on the enzyme, and may be either a starch or a glycoprotein. GH27 members are retaining enzymes that cleave their substrates via an acid/base-catalyzed, double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively.
Pssm-ID: 269893 [Multi-domain] Cd Length: 271 Bit Score: 411.18 E-value: 4.77e-144
Glycoside hydrolases, clan D; This group of glycosyl hydrolase families is comprised of ...
35-291
1.63e-32
Glycoside hydrolases, clan D; This group of glycosyl hydrolase families is comprised of glycosyl hydrolase family 31 (GH31), family 36 (GH36), and family 27 (GH27). These structurally and mechanistically related protein families are retaining enzymes that cleave their substrates via an acid/base-catalyzed, double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively. They have a wide range of functions including alpha-glucosidase, alpha-xylosidase, 6-alpha-glucosyltransferase, 3-alpha-isomaltosyltransferase, alpha-N-acetylgalactosaminidase, stachyose synthase, raffinose synthase, and alpha-1,4-glucan lyase.
Pssm-ID: 269891 [Multi-domain] Cd Length: 253 Bit Score: 123.50 E-value: 1.63e-32
glycosyl hydrolase family 36 (GH36); GH36 enzymes occur in prokaryotes, eukaryotes, and ...
35-285
9.92e-13
glycosyl hydrolase family 36 (GH36); GH36 enzymes occur in prokaryotes, eukaryotes, and archaea with a wide range of hydrolytic activities, including alpha-galactosidase, alpha-N-acetylgalactosaminidase, stachyose synthase, and raffinose synthase. All GH36 enzymes cleave a terminal carbohydrate moiety from a substrate that varies considerably in size, depending on the enzyme, and may be either a starch or a glycoprotein. GH36 members are retaining enzymes that cleave their substrates via an acid/base-catalyzed, double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively.
Pssm-ID: 269892 [Multi-domain] Cd Length: 299 Bit Score: 68.40 E-value: 9.92e-13
Melibiase; Glycoside hydrolase families GH27, GH31 and GH36 form the glycoside hydrolase clan ...
40-118
3.99e-05
Melibiase; Glycoside hydrolase families GH27, GH31 and GH36 form the glycoside hydrolase clan GH-D. Glycoside hydrolase family 36 can be split into 11 families, GH36A to GH36K. This family includes enzymes from GH36A-B and GH36D-K and from GH27.
Pssm-ID: 307952 Cd Length: 347 Bit Score: 45.46 E-value: 3.99e-05
Database: CDSEARCH/cdd Low complexity filter: no Composition Based Adjustment: yes E-value threshold: 0.01
References:
Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
of the residues that compose this conserved feature have been mapped to the query sequence.
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