Disease relevance of yihQ

• The proteins encoded in the yicI and yihQ gene of Escherichia coli have similarities in the amino acid sequences to glycoside hydrolase family 31 enzymes, but they have not been detected as the active enzymes [1].
• Identification and enzymatic characterization of the maltose-inducible alpha-glucosidase MalL (sucrase-isomaltase-maltase) of Bacillus subtilis [2].
• Amongst others, alpha-glucosidase activity is one of the most important biochemical features, which differentiates E. sakazakii from other species in the family Enterobacteriaceae and has therefore been used as a selective marker in the development of differential media [3].
• Molecular characterization of the alpha-glucosidase activity in Enterobacter sakazakii reveals the presence of a putative gene cluster for palatinose metabolism [3].
• Two alpha-glucosidase encoding genes (aglA and aglB) from Bifidobacterium adolescentis DSM 20083 were isolated and characterized [4].

High impact information on yihQ

• Fusion proteins of monomeric alpha-glucosidase from Saccharomyces cerevisiae containing N- or C-terminal hexa-arginie peptides were expressed in the cytosol of Escherichia coli in soluble form [5].
• EF-G and IF2 promote the functional folding of citrate synthase and alpha-glucosidase after urea denaturation [6].
• Reorientating sucrose density gradient centrifugation of culture medium showed that alkaline phosphatase, aminopeptidase N and alpha-glucosidase were predominantly associated with particles of peak modal density 1.19 g/ml in both groups, confirming that enteropathogenic E coli accelerate release of microvillar membrane enzymes as vesicles [7].
• In contrast, gamma-glutamyl transferase activity was enhanced in brush border fragments of slightly increased modal density, but there were no changes in the activities of the carbohydrases, zinc-resistant alpha-glucosidase, maltase, sucrase, and lactase or of the peptidase, leucyl-2-naphthylamidase [8].
• Arabidopsis contains at least three alpha-glucosidase genes; Aglu-1 and Aglu-3 are sequenced and Aglu-2 is known from six expressed sequence tags [9].

Chemical compound and disease context of yihQ

• YihQ exhibits the hydrolysis activity against alpha-glucosyl fluoride, and so is an alpha-glucosidase, although the natural substrates, such as alpha-glucobioses, are scarcely hydrolyzed. alpha-Glucosidase has been found for the first time in E. coli [1].
• The cellular response of Escherichia coli to overproduction of the insoluble heterologous protein alpha-glucosidase of Saccharomyces cerevisiae during a glucose-limited fed-batch fermentation was analyzed on the transcriptional and the translational levels [10].
• Using standard growth conditions (LB medium, 37 degrees C, induction with 5 mM IPTG) yeast alpha-glucosidase PI expressed under the control of the regulated tac-hybrid promoter results in the synthesis of insoluble aggregated alpha-glucosidase granules in Escherichia coli [11].
• The cloned gene was expressed in Escherichia coli cells to produce the alpha-glucosidase, which hydrolyzes not only maltose, but also soluble starch [12].

Biological context of yihQ

• Insertional mutagenesis of malL resulted in a complete inactivation of the maltose-inducible alpha-glucosidase activity in crude protein extracts and a Mal- phenotype [2].
• Copy-DNA cloning and characterisation of a potato alpha-glucosidase: expression in Escherichia coli and effects of down-regulation in transgenic potato [13].
• In order to isolate the structural gene involved in sucrose utilization, we screened a sucrose-induced Candida albicans cDNA library for clones expressing alpha-glucosidase activity [14].
• A gene coding for a putative alpha-glucosidase has been identified in the open reading frame yvdL (now termed malL), which was sequenced as part of the Bacillus subtilis genome project [2].
• The nucleotide sequence of a 4.39-kb DNA fragment encoding the alpha-glucosidase gene of Candida tsukubaensis is reported [15].

Anatomical context of yihQ

• Analysis of the aggregated protein fraction revealed a remarkably inhomogeneous composition of the alpha-glucosidase inclusion bodies [10].
• Synthesis of alpha-amylase and alpha-glucosidase by membrane bound ribosomes from Bacillus licheniformis [16].

Associations of yihQ with chemical compounds

• Chromosomal inactivation of malR led to reduced maltose utilization, although alpha-glucosidase activity in the malR mutant was slightly higher than in the wild type [17].
• It was shown that after removal of alpha-glucosidase activity, GTF-D transglucosylated catechin with the highest efficiency [18].
• Enzymatically active, recombinant alpha-glucosidase was synthesized and secreted from the yeast upon induction with methanol [19].
• Thus, the cloned gene confers a dominant selectable phenotype on transformed strains of S. cerevisiae which are otherwise unable to grow in nutrient media containing maltose, dextrin or other alpha-1.4-linked alpha-D-glucopyranosides, specifically hydrolysed by the alpha-glucosidase [20].
• Enzymatic treatments of jejunal sections demonstrated that N- and O-glycosidases, and several exoglycosidases did not affect binding, whereas reduced binding was observed with ceramide glycanase and alpha-glucosidase, and was completely abolished following neuraminidase treatment [21].

Regulatory relationships of yihQ

• Molecular cloning and nucleotide sequence of the groEL gene from the alkaliphilic Bacillus sp. strain C-125 and reactivation of thermally inactivated alpha-glucosidase by recombinant GroEL [22].

Other interactions of yihQ

• Here we demonstrate that the general stress response, which is connected to the stress response regulator sigmas (sigma38, rpoS gene product), is suppressed during strong overproduction of a heterologous alpha-glucosidase [23].

Analytical, diagnostic and therapeutic context of yihQ

• In attempt to convert YicI into an alpha-glucosidase these elements have been targeted by site-directed mutagenesis [24].
• Synthesis of these proteins also occurred in isolated aleurones after treatment with gibberellin, and this was accompanied by a 14-fold increase in alpha-glucosidase enzyme activity [19].
• The MF bioreactor allowed a cell concentration of 50 g/L dry weight and a corresponding alpha-glucosidase production of 11,500 U/L [25].
• In vitro chain completion and immunoprecipitation showed that alpha-glucosidase and alpha-amylase were synthesized by membrane bound and not by soluble ribosomes [16].
• Molecular cloning, sequencing, and expression of a cDNA encoding alpha-glucosidase from Mucor javanicus [12].

References