Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mutant strain of Saccharomyces cerevisiae (D10-ER1) has been isolated after a two-step mutagenesis of strain 4059-358D (SUC 1) using ethyl methane sulfonate. Cells of this new strain produced a level of total invertase equaling that of 4059 but contained only trace amounts of the small, internal, aglycan form of the enzyme (less than 0.1% of total in D10-ER1 compared with 6% in 4059). When D10.ER1 was crossed with an invertase-hyperproducing strain dgr3 (SUC3), progeny were isolated (HZ400-5A and HZ400-2C) in which levels of total invertase had at least quadrupled. The percentage of small invertase, however, remained insignificant. Levels of small invertase in strain HZ400-5A were determined by affinity chromatography on conconavalin A-Sepharose, gel permeation chromatography, and isopycnic centrifugation in CsCl. The large invertase of the SUC1 yeasts described here was found to contain a form apparently greater in size than the large invertase of the SUC2 strain FH4C; this probably reflects a higher content of carbohydrate. The overall results of this study do not support a direct structural relationship between large and small invertases. The implications on invertase biosynthesis and structure are discussed.
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PMID:Relationship of large and small invertases in Saccharomyces: mutant selectively deficient in small invertase. 35 25

Fructooligosaccharides stimulate the growth of intestinal bifidobacteria which are related to the favorable health and nutrition of humans and other animals. Since the efficient amount of fructooligosaccharide for an adult human is relatively large (about 5 g per day), its addition to daily foods like bakery goods might be beneficial. However, commercial Bakers' yeast hydrolyses fructooligosaccharides by the action of invertase encoded in SUC genes and ferments the resulting monosaccharides. According to the findings that strains carrying the MAL-constitutive gene and lacking the SUC gene fermented sucrose and not fructooligosaccharide, we constructed a sucrose-fermenting strain, YOY920, incapable of hydrolysing fructooligosaccharide, by cross-breeding a baking strain and a laboratory strain. In a molasses medium, the cell yield of YOY920 was comparable to that of a baking strain FSC6001, and much higher than that of the non-sucrose-fermenting strains. Although fructooligosaccharide inhibited the dough leavening ability of YOY920, white bread containing fructooligosaccharide could be produced in the defined dough formula using the new strain.
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PMID:Construction of a sucrose-fermenting bakers' yeast incapable of hydrolysing fructooligosaccharides. 136 32

The RPS5 gene has been characterised through its ability to reduce invertase production by the SUC5 gene. In this paper we show that RPS5 acts by maintaining low levels of SUC5 mRNA. We also show that RPS5 acts on the SUC1 and SUC4 genes but not on SUC2 and SUC3, which are members of the SUC family. RPS5 also shows a pleiotropic effect on the amount of mitochondrial cytochromes.
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PMID:Phenotype traits associated with different alleles at the RPS5 locus in Saccharomyces cerevisiae. 152 57

Transformation to generate multiple copies of regulatory DNA sequences has been used to study the interactions between regulatory proteins and their target sequences, since a high copy number of these sequences may titrate trans-acting regulatory proteins. We have analyzed the synthesis of invertase in yeast strains carrying different SUC genes transformed with the multiple-copy plasmid pSH143, a derivative of pJDB207 containing the promoter and upstream regulatory sequences of SUC4. The results obtained seem to be strain dependent. Under repressing conditions a high copy number of SUC4 promoter regions may cause increased expression of the invertase genes resulting in the synthesis of external glycosylated protein. A similar result was obtained under de-repressing conditions since transformants from some strains showed higher levels of activity. These results suggest that transcriptional regulatory (negative) factors may become limiting when the copy number of their target DNA sequences is increased. This effect may depend on the amount of active repressor molecules as well as on their affinity for SUC4 upstream sequences. This is discussed on the basis of the nucleotide sequences of SUC promoters.
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PMID:Multiple copies of SUC4 regulatory regions may cause partial de-repression of invertase synthesis in Saccharomyces cerevisiae. 161 32

A series of deletions were made at upstream region of SUC2 gene with the direction from about -900 bp to the initiation codon. The DNA fragments, which contain SUC22 gene and its deleted upstream region, were inserted into multicopy plasmid. After transforming resulted plasmid into SUC strain, the invertase activities produced by the transformants were determined. Under glucose repressing condition, the glycosylated invertase produced by transformants with deletion from -636 bp to -179 bp of SUC2 gene were gradually increased. The transformants with deletion down to -223 bp and -179 bp could produce about 100 times higher glycosylated invertase activity as compared to wild type. Under glucose derepressing condition, the glycosylated invertase produced by transformants with deletion from -395 bp to -179 bp of SUC2 gene were only slightly more than that produced under glucose repressing condition. Under either glucose repressing or derepressing condition, the transformants with deletion at -89 bp and -41 bp produced only a little of glycosylated invertase, while they produced remarkably higher nonglycosylated invertase activity.
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PMID:[The effects of upstream region of SUC2 gene on its expression]. 188 28

suc2 degrees is a naturally occurring amber mutant allele of the yeast invertase structural gene SUC2. Strains carrying suc2 degrees had only 10% of the wild type invertase-specific mRNA level. Amber suppressors, which allowed suc2 degree strains to ferment sucrose caused an increase of the SUC-specific mRNA level.
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PMID:Nonsense suppressors partially revert the decrease of the mRNA level of a nonsense mutant allele in yeast. 231 Nov 29

A three step purification procedure for trehalase from Saccharomyces cerevisiae with a recovery of 76% of the original activity is presented. The enzyme was activated by a heat shock treatment prior to homogenization of the cells. A mutant strain deleted in SUC genes was used to avoid contamination by invertase. The lyophylized enzyme was stable for, at least, 5 months and could be used to determine trehalose in the range 25 to 500 nmol. The preparation was free of inspecific phosphatases allowing for trehalose determinations in yeast cell free extracts and in insect hemolymph.
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PMID:Determination of trehalose in biological samples by a simple and stable trehalase preparation. 266 12

Six unlinked loci for invertase structural genes are known in the yeast Saccharomyces cerevisiae: SUC1-SUC5 and SUC7. These genes are similar in structure and expression but not identical. Different yeast strains possess none, one or several of these genes. We have isolated the genes SUC1-SUC5, subcloned them into the multicopy vector YEp24 and compared the expression of the five SUC genes in one recipient strain. SUC2 was isolated by transformation of a suc0 strain with a gene pool and complementation to sucrose fermentation. SUC4 was cloned from a minipool of chromosomal fragments which were shown to contain SUC4 by Southern hybridization. SUC1, SUC3 and SUC5 were isolated using the method of plasmid eviction. A plasmid containing regions flanking SUC4 was integrated next to these SUC genes. The plasmid together with the SUC genes were then cut out of the chromosome using an appropriate restriction endonuclease. The length of chromosomal DNA fragments containing the different SUC genes were 4.8 kb for SUC1, 5.2 kb for SUC2, 4.8 kb for SUC3, 12.8 kb for SUC4 and 17.2 kb for SUC5. Fragments containing the complete SUC genes and the sequences controlling their expression were subcloned into YEp24 and transformed into a strain without any active invertase gene. Invertase activity of transformants was measured after growth repressing (8% glucose) and derepressing (2% raffinose) conditions. As expected from results with strains carrying the individual SUC genes in a chromosomal location, the SUC genes were expressed to a different extent.
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PMID:Cloning and expression on a multicopy vector of five invertase genes of Saccharomyces cerevisiae. 283 91

Integrative transformation of yeast with gapped DNA fragments results in single or multiple integration into the yeast genome via homologous recombination. A sequence of yeast DNA was found which favours multiple integration even when the strategy of gene replacement is used. This strategy by which the transformed DNA fragment replaces its chromosomal homologue rather than simply integrating into the genome usually occurs as a single exchange event. The described region is unique and lies near a telomere about 5 kb proximal to the SUC4 locus on chromosome XIII. DNA from this region was used as a vehicle for the integration of different SUC genes coding for invertase. Most of the sucrose fermenting transformants isolated carried between two and seven copies of the SUC genes. These transformants overproduced invertase even though there was no selective pressure for high invertase activity in these experiments. I conclude that this region is highly recombinogenic and favours multiple integration of DNA fragments. This region could be used for stable multiple integration of heterologous genes into the yeast genome for over-production of the respective gene product.
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PMID:A region in the yeast genome which favours multiple integration of DNA via homologous recombination. 283 99

In the yeast Saccharomyces cerevisiae six unlinked structural genes for invertase, the SUC genes, are known. We sequenced about 800 bp of the 5' non-coding region and the first 220 bp of the coding region of the genes SUC1, SUC3, SUC4 and SUC5 and compared them with the previously sequenced genes SUC2 and SUC7 (Sarokin and Carlson 1985a). All are highly homologous within the coding region but in the non-coding region SUC1 shows some differences and SUC2 is more highly diverged. Two different kinds of TATA boxes were identified: the more strongly expressed genes SUC1, 2 and 4 have the sequence TATAAA and the more weakly expressed genes SUC3, 5 and 7 have TACAAA. Though the SUC1 sequence is in general more homologous to the other SUC genes, the region between -140 and +100 of SUC1 is nearly identical to SUC2. This could be due to a gene conversion between SUC1 and the silent suc2 degrees allele which occurs in the strains carrying SUC1. Within the upstream regions of all the SUC genes three regions with palindromic sequences analogous to stem and loop structures were identified. Comparable structures could be detected in similar positions in the upstream sequences of the divergently transcribed yeast gene pairs MAL6S-MAL6T and GAL1-GAL10. Implications for the importance of these structures in the regulation and initiation of transcription are discussed.
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PMID:Structural analysis of the 5' regions of yeast SUC genes revealed analogous palindromes in SUC, MAL and GAL. 283 32


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