Search results for "saccharomyces"
showing 10 items of 861 documents
Identification and structural characterization of O-beta-ribosyl-(1"----2')-adenosine-5"-phosphate in yeast methionine initiator tRNA.
1990
We report in this paper on the complete structure determination of the modified nucleotide A*, now called Ar(p), that was previously identified in yeast methionine initiator tRNA as an isomeric form of O-ribosyl-adenosine bearing an additional phosphoryl-monoester group on its ribose2 moiety. By using the chemical procedure of periodate oxidation and subsequent beta-elimination with cyclohexylamine on mono- and dinucleotides containing Ar(p), we characterized the location of the phosphate group on the C-5" of the ribose2 moiety, and the linkage between the two riboses as a (1"----2')-glycosidic bond. Since the structural difference between phosphatase treated Ar(p) and authentic O-alpha-rib…
Fractionated precipitation of acid macropolyanions by dialysis, a simple method for the estimation of DNA in complex biological samples.
1976
Abstract After efficient extraction by para-aminosalicylate, (hopping, grinding and eventual sonication, the macropolyanions are transformed into their cetyltrimethylammonium salts. These have differing solubilities, strongly depending on ionic strength. The cationic detergent-macropolyanionic salts are solubilized by high salt concentration. Salt is then dialysed out, rendering the polyanions highly insoluble in a sequential fashion. The insolubilized components are determined quantitatively by monitoring turbidity, which in case of DNA is strictly proportionate to its concentration. This relation is not affected by other components. This makes DNA determination possible even in crude aque…
Hypusinated eIF5A is required for the translation of collagen.
2021
ABSTRACT Translation of mRNAs that encode peptide sequences with consecutive prolines (polyproline) requires the conserved and essential elongation factor eIF5A to facilitate the formation of peptide bonds. It has been shown that, upon eIF5A depletion, yeast ribosomes stall in polyproline motifs, but also in tripeptide sequences that combine proline with glycine and charged amino acids. Mammalian collagens are enriched in putative eIF5A-dependent Pro-Gly-containing tripeptides. Here, we show that depletion of active eIF5A in mouse fibroblasts reduced collagen type I α1 chain (Col1a1) content, which concentrated around the nuclei. Moreover, it provoked the upregulation of endoplasmic reticul…
Lipid content of Saccharomyces cerevisiae strains with different degrees of ethanol tolerance
1992
We analysed the fatty acid and sterol compositions of various Saccharomyces cerevisiae strains with ethanol tolerance varying from 4% to 12% (v/v) ethanol and at different concentrations of ethanol. The results we obtained agree with the existence of a relationship between membrane fluidity and ethanol tolerance but they do not support a direct role of unsaturated fatty acids in this tolerance. On the other hand, they support the importance of ergosterol in this phenomenon.
Relationships between metabolic fluxes and enzyme amino acid composition
2013
AbstractMetabolic fluxes are a key parameter of metabolic pathways being closely related to the kinetic properties of enzymes and could be conditional on their sequence characteristics. This study examines possible relationships between the metabolic fluxes and the amino acid (AA) composition (AAC) for enzymes from the yeast Saccharomyces cerevisiae glycolysis pathway. Metabolic fluxes were quantified by the COPASI tool using the kinetic models of Hynne and Teusink at 25 mM, 50 mM, and 100 mM of external glucose or employing literature data for cognate kinetic or stoichiometric models. The enzyme sequences were taken from the UniProtKB, and the AAC computed by the ExPASy/ProtParam tool. Mul…
Sequence of a new tRNALeu(U∗AA) from brewer's yeast
1991
The nucleotide sequence of a new tRNA(Leu)(anticodon U*AA) from Saccharomyces cerevisiae which could recognize exclusively the UUA codon has been determined. Its primary structure is: pGGAGGGUUGm2GCac4CGAGDGmGDCDAAGGCm2(2)GGCAGACmUU*AAm1GA++ + psi CUGUUGGACGGUUGUCCGm5CGCGAGT psi CGm1A(orA)ACCUCGCAUCCUUCACCA. This tRNA has a large extraloop and contains 15 modified nucleotides. So far it is the third isoacceptor tRNA for leucine in yeast. It has 61% homology with tRNA(Leu)(anticodon m5CAA) and 63% homology with tRNA(Leu)(anticodon UAG), the two other known yeast tRNAs(Leu).
RAS proteins and control of the cell cycle inSaccharomyces cerevisiae
1995
Genes related to the mammalian H-, K-, and N-ras oncogenes were identified in S. cerevisiae by DNA hybridization techniques (for reviews, see Tamanoi, 1988; Gibbs and Marshall, 1989; Broach and Deschenes, 1990). According to the rules of yeast genetics (dominant genes are indicated by three capital letters followed by a number), the yeast genes were denominated RAS1 and RAS2 (collectively referred to as RAS). The corresponding RAS1 and RAS2 proteins were 309 and 322 amino acids long, respectively. The sequence similarity between the human and yeast proteins was very high, reaching 90% identity at the level of the N-terminal 80 amino acids. As a consequence, perfect sequence conservation was…
O-linked mannose composition of secreted invertase of Saccharomyces cerevisiae
1989
The secreted invertase (EC 3.2.1.26) of Saccharomyces cerevisiae is a glycoenzyme that contains N- and O-linked mannoses in 40/1 proportion. The small amount of mannose chains O-linked to invertase is distributed as follows: mannose (20%), mannobiose (50%), mannotriose (6%), mannotetraose (7%) and mannopentaose (17%).
Role of glycosylation in the incorporation of intrinsic mannoproteins into cell walls of Saccharomyces cerevisiae.
1989
Cell wall mannoproteins from Saccharomyces cerevisiae are completely or partially incorporated into their final location when N-glycosylation is inhibited by tunicamycin. These include a 90–100 kDa species still containing O-linked oligomannose chains, derived from a N-glycosylated material larger than 120 kDa; and a 30.5 kDa peptide lacking mannose residues, derived from a 33 kDa species. For both species, the growth temperature influences the level of incorporation of the non N-glycosylated molecules. Secretion of the peptides lacking N-linked saccharide chains follows the route defined by sec mutants.
Temporal aspects of the O-glycosylation of Saccharomyces cerevisiae mannoproteins
1986
Abstract Cleavage of the O-glycosyl bonds of Saccharomyces cerevisiae cell wall mannoproteins by β-elimination resulted in the release of about 8% of the carbohydrate in the form of mannose and other low molecular weight oligomannosaccharides (mannose to mannopentaose), leaving 92% mannose still covalently linked to the peptide, and suggesting that this alkali-resistant fraction was N-glycosidically linked. At the non-permissive temperature, S. cerevisiae sec mutants accumulated in the cytoplasm mannoproteins with different degrees of O- and N-glycosylation. The glycoproteins of mutant sec 20-1 contained 60% of the carbohydrate linked by N-bonds, the remainder being O-glycosidically linked.…