Alpha amylase catalytic domain found in Glycosyltrehalose trehalohydrolase (also called Maltooligosyl trehalose Trehalohydrolase). Glycosyltrehalose trehalohydrolase (GTHase) was discovered as part of a coupled system for the production of trehalose from soluble starch. In the first half of the reaction, glycosyltrehalose synthase (GTSase), an intramolecular glycosyl transferase, converts the glycosidic bond between the last two glucose residues of amylose from an alpha-1,4 bond to an alpha-1,1 bond, making a non-reducing glycosyl trehaloside. In the second half of the reaction, GTHase cleaves the alpha-1,4 glycosidic bond adjacent to the trehalose moiety to release trehalose and malto-oligosaccharide. Like isoamylase and other glycosidases that recognize branched oligosaccharides, GTHase contains an N-terminal extension and does not have the conserved calcium ion present in other alpha amylase family enzymes. 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; 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 the 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. Glycosyltrehalose Trehalohydrolase Maltooligosyltrehalose Trehalohydrolase

malto-oligosyltrehalose trehalohydrolase. Members of this family are the trehalose biosynthetic enzyme malto-oligosyltrehalose trehalohydrolase, formally known as 4-alpha-D-{(1->4)-alpha-D-glucano}trehalose trehalohydrolase (EC 3.2.1.141). It is the TreZ protein of the TreYZ pathway for trehalose biosynthesis, and alternative to the OtsAB system. [Energy metabolism, Biosynthesis and degradation of polysaccharides]

1,4-alpha-glucan branching enzyme [Carbohydrate transport and metabolism].

Alpha amylase catalytic domain found in an uncharacterized protein 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; 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 the 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 (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.

N-terminal Early set domain associated with the catalytic domain of Maltooligosyl trehalose trehalohydrolase (also called Glycosyltrehalose trehalohydrolase) and similar proteins. E or "early" set domains are associated with the catalytic domain of Maltooligosyl trehalose trehalohydrolase (MTHase) and similar proteins at the N-terminal end. This subfamily also includes bacterial alpha amylases and 1,4-alpha-glucan branching enzymes which are highly similar to MTHase. Maltooligosyl trehalose synthase (MTSase) and MTHase work together to produce trehalose. MTSase is responsible for converting the alpha-1,4-glucosidic linkage to an alpha,alpha-1,1-glucosidic linkage at the reducing end of the maltooligosaccharide through an intramolecular transglucosylation reaction, while MTHase hydrolyzes the penultimate alpha-1,4 linkage of the reducing end, resulting in the release of trehalose. The N-terminal domain of MTHase may be related to the immunoglobulin and/or fibronectin type III superfamilies. These domains are associated with different types of catalytic domains at either the N-terminal or C-terminal end and may be involved in homodimeric/tetrameric/dodecameric interactions. Members of this family include members of the alpha amylase family, sialidase, galactose oxidase, cellulase, cellulose, hyaluronate lyase, chitobiase, and chitinase, among others.

1.4Angstrom Resolution Crystal Structure of Putative alpha Amylase from Salmonella typhimurium. [Salmonella enterica subsp. enterica serovar Typhimurium str. LT2]

Crystalstructure of Deinococcus radiodurans maltooligosyltrehalose trehalohydrolase [Deinococcus radiodurans]

Crystalstructure of Deinococcus radiodurans maltooligosyltrehalose trehalohydrolase in complex with trehalose [Deinococcus radiodurans],2BHZ_A Crystal structure of Deinococcus radiodurans maltooligosyltrehalose trehalohydrolase in complex with maltose [Deinococcus radiodurans R1],2BXY_A Is radiation damage dependent on the dose-rate used during macromolecular crystallography data collection [Deinococcus radiodurans],2BXZ_A Is radiation damage dependent on the dose-rate used during macromolecular crystallography data collection [Deinococcus radiodurans],2BY0_A Is radiation damage dependent on the dose-rate used during macromolecular crystallography data collection [Deinococcus radiodurans],2BY1_A Is radiation damage dependent on the dose-rate used during macromolecular crystallography data collection [Deinococcus radiodurans R1],2BY2_A Is radiation damage dependent on the dose-rate used during macromolecular crystallography data collection [Deinococcus radiodurans R1],2BY3_A Is radiation damage dependent on the dose-rate used during macromolecular crystallography data collection [Deinococcus radiodurans]

Crystalstructure of glycosyltrehalose trehalohydrolase (E283Q) complexed with maltoheptaose [Saccharolobus solfataricus],3VGH_A Crystal structure of glycosyltrehalose trehalohydrolase (E283Q) complexed with maltotriosyltrehalose [Saccharolobus solfataricus]

CRYSTALSTRUCTURE OF GLYCOSYLTREHALOSE TREHALOHYDROLASE FROM SULFOLOBUS SOLFATARICUS [Saccharolobus solfataricus]

Malto-oligosyltrehalose trehalohydrolase OS=Deinococcus radiodurans (strain ATCC 13939 / DSM 20539 / JCM 16871 / LMG 4051 / NBRC 15346 / NCIMB 9279 / R1 / VKM B-1422) OX=243230 GN=treZ PE=1 SV=1

Malto-oligosyltrehalose trehalohydrolase OS=Rhizobium sp. (strain M-11) OX=269089 GN=treZ PE=3 SV=1

Malto-oligosyltrehalose trehalohydrolase OS=Arthrobacter sp. (strain Q36) OX=104027 GN=treZ PE=3 SV=1

Malto-oligosyltrehalose trehalohydrolase OS=Saccharolobus solfataricus OX=2287 GN=treZ PE=1 SV=2

Malto-oligosyltrehalose trehalohydrolase OS=Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2) OX=273057 GN=treZ PE=1 SV=1