THE ROLE OF SACCHAROMYCES CEREVISIAE WINE YEAST IN THE HYDROLYSIS OF GLYCOCONJUGATED AROMA PRECURSORS DURING WINEMAKING

2007 ◽  
pp. 155-160
Author(s):  
M. Ugliano ◽  
A. Rinaldi ◽  
A. Gambuti ◽  
L. Moio
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Wine Yeast ◽  
Aroma Precursors ◽  
Hydrolysis Of

scholarly journals Structure and activity of the Saccharomyces cerevisiae dUTP pyrophosphatase DUT1, an essential housekeeping enzyme

2011 ◽  
Vol 437 (2) ◽  
pp. 243-253 ◽  
Author(s):  
Anatoli Tchigvintsev ◽  
Alexander U. Singer ◽  
Robert Flick ◽  
Pierre Petit ◽  
Greg Brown ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Mechanisms ◽  
Site Directed Mutagenesis ◽  
Saturation Curve ◽  
Significant Activity ◽  
Active Site Residues ◽  
Living Organisms ◽  
Hydrolysis Of

Genomes of all free-living organisms encode the enzyme dUTPase (dUTP pyrophosphatase), which plays a key role in preventing uracil incorporation into DNA. In the present paper, we describe the biochemical and structural characterization of DUT1 (Saccharomyces cerevisiae dUTPase). The hydrolysis of dUTP by DUT1 was strictly dependent on a bivalent metal cation with significant activity observed in the presence of Mg2+, Co2+, Mn2+, Ni2+ or Zn2+. In addition, DUT1 showed a significant activity against another potentially mutagenic nucleotide: dITP. With both substrates, DUT1 demonstrated a sigmoidal saturation curve, suggesting a positive co-operativity between the subunits. The crystal structure of DUT1 was solved at 2 Å resolution (1 Å=0.1 nm) in an apo state and in complex with the non-hydrolysable substrate α,β-imido dUTP or dUMP product. Alanine-replacement mutagenesis of the active-site residues revealed seven residues important for activity including the conserved triad Asp87/Arg137/Asp85. The Y88A mutant protein was equally active against both dUTP and UTP, indicating that this conserved tyrosine residue is responsible for discrimination against ribonucleotides. The structure of DUT1 and site-directed mutagenesis support a role of the conserved Phe142 in the interaction with the uracil base. Our work provides further insight into the molecular mechanisms of substrate selectivity and catalysis of dUTPases.

Functional analysis of the ALD gene family of Saccharomyces cerevisiae during anaerobic growth on glucose: the NADP+-dependent Ald6p and Ald5p isoforms play a major role in acetate formation

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2209-2220 ◽  
Author(s):  
Florence Saint-Prix ◽  
Linda Bönquist ◽  
Sylvie Dequin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Alternative Pathway ◽  
Wine Yeast ◽  
Anaerobic Growth ◽  
Acetate Production ◽  
Key Enzyme ◽  
Acetate Formation ◽  
First Time

In Saccharomyces cerevisiae, acetate is formed by acetaldehyde dehydrogenase (ACDH), a key enzyme of the pyruvate dehydrogenase (PDH) bypass, which fulfils the essential task of generating acetyl-CoA in the cytosol. The role of the five members of the ACDH family (ALD genes) was investigated during anaerobic growth on glucose. Single and multiple aldΔ mutants were generated in the wine-yeast-derived V5 and laboratory CEN.PK strains and analysed under standard (YPD 5 % glucose) and wine (MS 20 % glucose) fermentation conditions. The deletion of ALD6 and ALD5 decreased acetate formation in both strains, demonstrating for the first time that the mitochondrial Ald5p isoform is involved in the biosynthesis of acetate during anaerobic growth on glucose. Acetate production of the ald4Δ mutant was slightly decreased in the CEN.PK strain during growth on YPD only. In contrast, the deletion of ALD2 or ALD3 had no effect on acetate production. The absence of Ald6p was compensated by the mitochondrial isoforms and this involves the transcriptional activation of ALD4. Consistent with this, growth retardation was observed in ald6Δald4Δ, and this effect was amplified by the additional deletion of ALD5. A aldΔ null mutant, devoid of ACDH activity, was viable and produced similar levels of acetate to the ald6Δald4Δald5Δ strain, excluding a role of Ald2p and Ald3p. Thus, acetate is mainly produced by the cytosolic PDH bypass via Ald6p and by a mitochondrial route involving Ald5p. An unknown alternative pathway can compensate for the loss of Ald6p, Ald4p and Ald5p.

L'hydrolyse des hétérosides terpéniques du Muscat a petits grains par les enzymes périplasmiques de Saccharomyces cerevisiae

OENO One ◽  
1988 ◽  
Vol 22 (3) ◽  
pp. 189 ◽  
Author(s):  
Philippe Darriet ◽  
Jean-Noël Boidron ◽  
Denis Dubourdieu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Cell ◽  
Cell Walls ◽  
Yeast Cells ◽  
Periplasmic Space ◽  
Enzymatic Extract ◽  
Periplasmic Extract ◽  
Glucosidase Activity ◽  
Aroma Precursors ◽  
Hydrolysis Of

<p style="text-align: justify;">Osidases located in periplasmic space of <em>Saccharomyces cerevisiae</em> are able to hydrolyse monoterpenes heterosides of Muscat grapes. To prepare the periplasmic extract, yeast cell walls are digested with <em>Zymolyase</em> in the presence of an osmotic protector to prevent lysis of the resulting protoplasts; periplasmic enzymes are liberated into the supernatant medium. Monoterpenes heterosides are incubated 48 or 72 hours at 25° C with either intact yeast cells or periplasmic enzymatic extract. Monoterpenes, especially gerianol and nerol, are liberated in these conditions. β-glucosidase activity seems to play an important rôle in these reactions.</p><p style="text-align: justify;">Fungal extracellular β-glucosidases are commonly strongly inhibited by glucose. Surprisingly, the activity of periplasmic yeast β-glucosidase is quite glucose independant. These results suggest that some periplasmic enzymes from yeast may be involved in the hydrolysis of varietal aroma precursors in wines.</p>

scholarly journals Dynamic Interactions of Ntr1-Ntr2 with Prp43 and with U5 Govern the Recruitment of Prp43 To Mediate Spliceosome Disassembly

2007 ◽  
Vol 27 (23) ◽  
pp. 8027-8037 ◽  
Author(s):  
Rong-Tzong Tsai ◽  
Chi-Kang Tseng ◽  
Pei-Jung Lee ◽  
Hsin-Chou Chen ◽  
Ru-Huei Fu ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Helicase ◽  
Stable Complex ◽  
Splicing Factors ◽  
Dynamic Interactions ◽  
Functional Complex ◽  
Hydrolysis Of

ABSTRACT The Saccharomyces cerevisiae splicing factors Ntr1 (also known as Spp382) and Ntr2 form a stable complex and can further associate with DExD/H-box RNA helicase Prp43 to form a functional complex, termed the NTR complex, which catalyzes spliceosome disassembly. We show that Prp43 interacts with Ntr1-Ntr2 in a dynamic manner. The Ntr1-Ntr2 complex can also bind to the spliceosome first, before recruiting Prp43 to catalyze disassembly. Binding of Ntr1-Ntr2 or Prp43 does not require ATP, but disassembly of the spliceosome requires hydrolysis of ATP. The NTR complex also dynamically interacts with U5 snRNP. Ntr2 interacts with U5 component Brr2 and is essential for both interactions of NTR with U5 and with the spliceosome. Ntr2 alone can also bind to U5 and to the spliceosome, suggesting a role of Ntr2 in mediating the binding of NTR to the spliceosome through its interaction with U5. Our results demonstrate that dynamic interactions of NTR with U5, through the interaction of Ntr2 with Brr2, and interactions of Ntr1 and Prp43 govern the recruitment of Prp43 to the spliceosome to mediate spliceosome disassembly.

scholarly journals SPO14 Separation-of-Function Mutations Define Unique Roles for Phospholipase D in Secretion and Cellular Differentiation in Saccharomyces cerevisiae

Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1431-1444 ◽  
Author(s):  
Simon A Rudge ◽  
Trevor R Pettitt ◽  
Chun Zhou ◽  
Michael J O Wakelam ◽  
JoAnne Engebrecht
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Phosphatidic Acid ◽  
Phospholipase D ◽  
Cellular Differentiation ◽  
Physiological Processes ◽  
Catalytically Active ◽  
Hydrolysis Of ◽  
Secretory Apparatus

Abstract In Saccharomyces cerevisiae, phospholipase D (PLD), encoded by the SPO14 gene, catalyzes the hydrolysis of phosphatidylcholine, producing choline and phosphatidic acid. SPO14 is essential for cellular differentiation during meiosis and is required for Golgi function when the normal secretory apparatus is perturbed (Sec14-independent secretion). We isolated specific alleles of SPO14 that support Sec14-independent secretion but not sporulation. Identification of these separation-of-function alleles indicates that the role of PLD in these two physiological processes is distinct. Analyses of the mutants reveal that the corresponding proteins are stable, phosphorylated, catalytically active in vitro, and can localize properly within the cell during meiosis. Surprisingly, the separation-of-function mutations map to the conserved catalytic region of the PLD protein. Choline and phosphatidic acid molecular species profiles during Sec14-independent secretion and meiosis reveal that while strains harboring one of these alleles, spo14S-11, hydrolyze phosphatidylcholine in Sec14-independent secretion, they fail to do so during sporulation or normal vegetative growth. These results demonstrate that Spo14 PLD catalytic activity and cellular function can be differentially regulated at the level of phosphatidylcholine hydrolysis.

Protective role of l ‐threonine against cadmium toxicity in Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Linru Huang ◽  
Zhijia Fang ◽  
Jian Gao ◽  
Jingwen Wang ◽  
Yongbin Li ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cadmium Toxicity ◽  
Protective Role

scholarly journals Molecular Basis of Fructose Utilization by the Wine Yeast Saccharomyces cerevisiae: a Mutated HXT3 Allele Enhances Fructose Fermentation

2007 ◽  
Vol 73 (8) ◽  
pp. 2432-2439 ◽  
Author(s):  
Carole Guillaume ◽  
Pierre Delobel ◽  
Jean-Marie Sablayrolles ◽  
Bruno Blondin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Basis ◽  
Alcoholic Fermentation ◽  
Wine Yeast ◽  
Glycolytic Flux ◽  
Hexose Transporter ◽  
Wine Yeasts ◽  
Yeast Saccharomyces Cerevisiae ◽  
High Fructose ◽  
Fructose Fermentation

ABSTRACT Fructose utilization by wine yeasts is critically important for the maintenance of a high fermentation rate at the end of alcoholic fermentation. A Saccharomyces cerevisiae wine yeast able to ferment grape must sugars to dryness was found to have a high fructose utilization capacity. We investigated the molecular basis of this enhanced fructose utilization capacity by studying the properties of several hexose transporter (HXT) genes. We found that this wine yeast harbored a mutated HXT3 allele. A functional analysis of this mutated allele was performed by examining expression in an hxt1-7Δ strain. Expression of the mutated allele alone was found to be sufficient for producing an increase in fructose utilization during fermentation similar to that observed in the commercial wine yeast. This work provides the first demonstration that the pattern of fructose utilization during wine fermentation can be altered by expression of a mutated hexose transporter in a wine yeast. We also found that the glycolytic flux could be increased by overexpression of the mutant transporter gene, with no effect on fructose utilization. Our data demonstrate that the Hxt3 hexose transporter plays a key role in determining the glucose/fructose utilization ratio during fermentation.

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