ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Somatic cell and molecular genetics 6 (1980), S. 653-665 
    ISSN: 1572-9931
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The synthesis of H1 histones was studied in nine mouse-human somatic cell hybrid clones containing reduced numbers of human chromosomes. The entire human genome could be accounted for karyologically and by the use of functional assays for specific enzyme markers encoded by human chromosomes. Chromatographic resolution and peptide mapping of species-specific H1 histones failed to reveal human H1 histones to a level of about 1% of total in the nine clones. In addition to the species-specific extinction of human H1 histones, effects were seen on the quantity of mouse H1 histone subtypes produced in four of the nine clones. The remaining five clones produced H1 histones qualitatively and quantitatively identical with those of the mouse parent, which was common to all nine clones. The results suggest at least two levels of control for H1 histone gene expression.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 49 (1989), S. 301-305 
    ISSN: 1432-0649
    Keywords: 82.50 ; 81.15
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have studied the photolysis of molybdenum hexacarbonyl by focused excimer laser radiation. It was found that electronically excited Mo atoms detected in the focus region of a KrF laser are due to a direct two photon absorption transition. The upper limit of the energy for complete dissociation of Mo(CO)6 has been derived from these results. Two photon dissociation in the gas phase should be the dominant process at metal film deposition on substrates positioned perpendicularly and near to the focus. Adding buffer gases to the organometallic vapor particle formation was observed in the whole irradiated gas volume. The analysis of scattered He-Ne laser light yields information about the density and size of these particles. Some conclusions are drawn with respect to structured metal film deposition with high spatial selectivity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 27 (1995), S. 306-308 
    ISSN: 1432-0983
    Keywords: Gene deletion ; Open reading frame ; Saccharomyces cerevisiae ; Polymerase chain reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The classical disruption method for yeast genes is by using in vitro deletion of the gene of interest, or of a part of it, with restriction enzymes. We are now routinely using a strategy that takes advantage of polymerase chain reactions (PCRs) which amplify large pieces of DNA. Since this approach results in a complete, precise deletion of the open reading frame, which is replaced by a unique restriction site, the ligated PCR can be used for the insertion of different markers of for two-step gene disruptions without an inserted marker. As we have now used this strategy for the deletion of more than ten genes we have in this report included some hints based on our experience.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Numerische Mathematik 75 (1997), S. 293-317 
    ISSN: 0945-3245
    Keywords: Mathematics Subject Classification (1991): 65L05, 65L70, 58F15, 58F12
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary. Each invariant set of a given dynamical system is part of the global attractor. Therefore the global attractor contains all the potentially interesting dynamics, and, in particular, it contains every (global) unstable manifold. For this reason it is of interest to have an algorithm which allows to approximate the global attractor numerically. In this article we develop such an algorithm using a subdivision technique. We prove convergence of this method in a very general setting, and, moreover, we describe the qualitative convergence behavior in the presence of a hyperbolic structure. The algorithm can successfully be applied to dynamical systems of moderate dimension, and we illustrate this fact by several numerical examples.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1476-5535
    Keywords: Keywords: Bacillus subtilis; riboflavin; 3,4-dihydroxy-2-butanone 4-phosphate synthase; GTP cyclohydrolase II
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: One of the proteins encoded by the riboflavin operon of Bacillus subtilis, RibA, was identified as the rate limiting enzyme in an industrial riboflavin producing strain. An additional single copy of the ribA gene was introduced into the sacB locus of the riboflavin production strain and was expressed constitutively from the medium strength vegI promoter. This led to improved riboflavin titers and yields of riboflavin on glucose of up to 25%. Both enzymatic activities of RibA, the 3,4-dihydroxy-2-butanone 4-phosphate synthase activity located in the N-terminal half of the protein and the GTP cyclohydrolase II activity of the C-terminal domain, are necessary for the improved riboflavin productivity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Current genetics 11 (1986), S. 217-225 
    ISSN: 1432-0983
    Keywords: Saccharomyces cerevisiae ; Gene cloning ; Invertase genes ; Multicopy vector
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0983
    Keywords: Yeast ; Pyruvate decarboxylase ; Gene expression ; Codon usage ; Gene fusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Three structural genes encode the pyruvate decarboxylase isoenzymes in the yeast Saccharomyces cerevisiae. PDC1 and PDC5 are active during glucose fermentation where PDC1 is expressed about six times more strongly than PDC5. Expression of PDC6 is weak and seems to be induced in ethanol medium. Consequently, pdc1Δ pdc5Δ double mutants do not ferment glucose and do not grow on glucose medium. Spontaneous mutants, derived from such a pdc1 pdc5 strain, were isolated which could again ferment glucose. They showed pyruvate decarboxylase activity due to a duplication of PDC6. The second copy of PDC6 was expressed under the control of the PDC1 promoter, which was still present in the pdc1 strain. However, the resulting PDC1-PDC6 fusion gene could only partially substitute for PDC1: to achieve normal growth and high pyruvate decarboxylase activity strains carrying PDC1-PDC6 required a functional PDC5 gene which is dispensable in a PDC1 wild-type background. Thus, expression of PDC5 depends on the state of the PDC1 locus: low in the PDC1 wild-type background and high in PDC1-PDC6 fusion strains and, as shown previously, in pdc1 mutants. The activation of PDC5 expression in PDC1-PDC6 strains may be due to particular properties of the PDC1-PDC6 fusion protein or simply to the weaker expression of PDC1-PDC6 in comparison to the wild-type PDC1 gene.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-0983
    Keywords: Yeast ; Glycolysis ; Glucose sensor ; Hexokinase ; Trehalose ; Signalling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Yeast cells defective in the GGS1 (FDP1/BYP1) gene are unable to adapt to fermentative metabolism. When glucose is added to derepressed ggs1 cells, growth is arrested due to an overloading of glycolysis with sugar phosphates which eventually leads to a depletion of phosphate in the cytosol. Ggs1 mutants lack all glucose-induced regulatory effects investigated so far. We reduced hexokinase activity in ggs1 strains by deleting the gene HXK2 encoding hexokinase PII. The double mutant ggs1Δ, hxk2Δ grew on glucose. This is in agreement with the idea that an inability of the ggs1 mutants to regulate the initiation of glycolysis causes the growth deficiency. However, the ggs1Δ, hxk2Δ double mutant still displayed a high level of glucose-6-phosphate as well as the rapid appearance of free intracellular glucose. This is consistent with our previous model suggesting an involvement of GGS1 in transport-associated sugar phosphorylation. Glucose induction of pyruvate decarboxylase, glucoseinduced cAMP-signalling, glucose-induced inactivation of fructose-1,6-bisphosphatase, and glucose-induced activation of the potassium transport system, all deficient in ggs1 mutants, were restored by the delection of HXK2. However, both the ggs1Δ and the ggs1Δ, hk2Δ mutant lack detectable trehalose and trehalose-6-phosphate synthase activity. Trehalose is undetectable even in ggs1Δ strains with strongly reduced activity of protein kinase A which normally causes a very high trehalose content. These data fit with the recent cloning of GGS1 as a subunit of the trehalose-6-phosphate synthase/phosphatase complex. We discuss a possible requirement of trehalose synthesis for a metabolic balance of sugar phosphates and free inorganic phosphate during the transition from derepressed to fermentative metabolism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-0983
    Keywords: Osmotic stress ; Glycerol ; Glycerol-3-phosphate dehydrogenase ; Glucose repression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Micro-organisms have developed systems to adapt to sudden changes in the environment. Here we describe the response of the yeastSaccharomyces cerevisiae to osmotic stress. A drop in the water activity (aw) of the medium following the addition of NaCl led to an immediate shrinkage of the cells. During the 2 h following the osmotic shock the cells partially restored their cell volume. This process depended on active protein synthesis. During the recovery period the cells accumulated glycerol intracellularly as a compatible solute and very little glycerol was leaking out of the cell. We have investigated in more detail the enzymes of glycerol metabolism and found that only the cytoplasmic glycerol-3-phosphate dehydrogenase was strongly induced. The level of induction was dependent on the yeast strain used and the degree of osmotic stress. The synthesis of cytoplasmic glycerol-3-phosphate dehydrogenase is also regulated by glucose repression. Using mutants defective in glucose repression (hxk2Δ), or derepression (snf1Δ), and with invertase as a marker enzyme, we show that glucose repression and the osmotic-stress response system regulate glycerol-3-phosphate dehydrogenase synthesis independently. We infer that specific control mechanisms sense the osmotic situation of the cell and induce responses such as the production and retention of glycerol.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1617-4623
    Keywords: Key wordsBacillus subtilis ; Riboflavin biosynthesis ; ribC ; Flavin kinase ; FAD synthase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A mutation leading to roseoflavin resistance and deregulated riboflavin biosynthesis was mapped in the genome of the riboflavin-overproducing Bacillus subtilis strains RB52 and RB50 at map position 147°. The chromosomal location indicates that the deregulating mutation in RB52 and RB50 is an allele of the previously identified ribC mutation. We cloned the ribC gene and found that it encodes a putative 36-kDa protein. Surprisingly, RibC has significant sequence similarity to flavin kinases and FAD synthases from various other bacterial species. By comparing the deduced amino acid sequence of RibC from the wild-type parent strain of RB50 with the RibC sequence from the riboflavin-overexpressing RB50 mutant we identified a point mutation that resulted in a Gly to Ser exchange in the C-terminal region of the product
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...