Compared with many different amylases that are able to hydrolyze only α-d-(1,4)- glycosidic bonds, maltogenic amylases exhibit catalytic versatility: hydrolysis of. The physiological functions of two amylolytic enzymes, a maltogenic amylase ( MAase) encoded by yvdF and a debranching enzyme (pullulanase) encoded by . Enzymatic characterization of a maltogenic amylase from. Lactobacillus gasseri ATCC expressed in Escherichia coli. Ko-Woon Oh a., Myo-Jeong Kim b.
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In this window In a new window. Although the catalytic properties and tertiary structure of MAase have been studied extensively 33its physiological role in the bacterial cell is yet to be elucidated. Purified glycogen from each B. An ultracentrifugation analysis further evidenced the dimerization of ThMA in solution as shown in Fig.
Dissolve mg maltotriose e. Read OD at nm. Related Content Load related web page information. A mono- or disaccharide occupying the space could serve as an acceptor molecule to compete with a water molecule for attacking enzyme-substrate intermediate catalyzed by the same catalytic armory as shown in Fig.
Proposed mechanism for competition of transglycosylation and hydrolysis reaction at the active site of ThMA. Two molecules of TVAII were also contained in the asymmetric unit of the crystals of the enzyme space group P 2 1 2 1 2 1. Maltose and maltodextrin utilization by Bacillus subtilis. The significantly larger amounts of G2 and G3 in the mdxE mutant than in the yvdF mutant may indicate that MAase degraded maltooligosaccharides in the periplasmic space before transportation into the cytoplasm.
The maltoegnic subunits, related by the molecular 2-fold axis lying on the figure, are labeled with different colors.
We have determined the structure of maltogenic amylase maltogfnic a Thermus strain ThMA. Transfer the solution to a ml volumetric flask, containing ml of 0. Clearly, the extra sugar-binding space was necessary in fitting the molecule.
Figure 4 Schematic drawings of products from reaction of acarbose with ThMA. The expression of many degradative enzymes that are produced in the late exponential phase of bacterial growth amylaee reported to be under the regulation of spo0Amalrogenic serves as a master regulator in controlling the life cycle of B. Therefore, the substrate profile and catalytic property of these enzymes would be best explained by the active site configuration in the dimeric state. It was not at all straightforward to solve the structure by using the phase information derived from MR, and additional phase information was obtained from three heavy atom derivative crystals Table I by MIR multiple isomorphous replacement method.
Vector for expression of the glycogen synthesis operon; Amp r Tet r. Open in a separate window. Thus, the pullulanase has a specific preference for side chains with DP of 3 to 5, which are the lowest DP that can be hydrolyzed by glycogen phosphorylase MAase that was present in the vicinity of the cellular amylawe during vegetative growth was redistributed into the cytoplasm of a prespore during sporulation Fig.
To replace the malZ gene of E. MAases, NPases, and CDases are intracellular enzymes, which implicates their biological roles in metabolizing small oligosaccharides, including CDs imported into the cells for energy generation, and storing them in the form of branched oligosaccharides under the condition of high concentration of glucose or maltose. One group of these, maltogenic amylases MAases; malltogenic EC 3.
Modes of action of acarbose hydrolysis and transglycosylation catalyzed by a thermostable maltogenic amylase, the gene for which was cloned from a Thermus strain. The starch-debranching enzymes amylaze and pullulanase are both involved in amylopectin biosynthesis in rice endosperm.
To investigate the specificity of pullulanase from B. Thus, MAase was confirmed to be involved in the use of maltooligosaccharides in vivo. In many bacteria and archaea, the activities of debranching enzymes are detected throughout the whole cell cycle and are even upregulated by maltose or starch 72629 Time course assays of glycogen formation and breakdown indicated that all of the mutants produced more glycogen than the wild type over 5 to 10 h of growth; the accumulation of glycogen in the amyX glg and glg DM strains was more significant than ma,togenic in the wild type.
Assay conditions being as follows: Dividing the large glycoside hydrolase family 13 into subfamilies: The resulting G4 would then be hydrolyzed by MAase to maltose as a major reaction product. Wild type yvdF mutant amyX amylasf yvdF amyX double mutant 5 1.
It is surprising that the new catalytic activities are gained mzltogenic by creating a new catalytic a,ylase, but most likely by creating the extra sugar-binding space at the active site.
The malZ gene of Escherichia colia member of the maltose regulon, encodes a maltodextrin glucosidase. The expression of MAase in E. The equilibrium was attained in 40 h.
Every other 20th residue positions are numbered. Glyoxysomal nature of microbodies complexed with lipid globules in Botryosphaeria dothidea. Hwang is also appreciated. The expression pattern of MAase in B. Overexpression and purification of pullulanase.
Physiological characterization of SusG, an outer membrane protein essential maltgenic starch utilization by Bacteroides thetaiotaomicron. The enzymatic properties and three-dimensional structure of AmyX from B.
Maltogenic amylase Bacillus sp Enzyme – Megazyme
Therefore, MAase seemed to be involved in the metabolism of carbohydrates in the stationary phase or during the process of sporulation. Preparation of glucose dehydrogenase GluDH reagent: Bacterial strains and plasmids used or constructed in this study. The property, if not all, is shared by other amylolytic enzymes with different names, including neopullulanases NPases; EC 3.
Results from a previous fractionation study amylaes MAase using spheroplasted cells suggested that the enzyme was localized mainly in the periplasmic space data not shownas Anderson and Salyers 1 reported for neopullulanase of Bacteroides thetaiotaomicron. Several groups of starch-hydrolyzing enzymes are known to harbor more than single enzyme activity.
The structure, an analytical centrifugation, and a size exclusion column chromatography proved that the enzyme is a dimer in solution. Table I Structure determination and crystallographic statistics. This article has been cited by other articles in PMC.