bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical separation and functional interaction of Kluyveromyces lactis and Saccharomyces cerevisiae ARS elements derived from killer plasmid DNA
Authors: Thompson Arthur , Oliver Stephen G. 
Published: May 2005

AbstractTeo DNA fragments which have autonomously replicating sequence (ARS) activity in both Saccharomyces cerevisiae and Kluyveromyces lactis have been isolated from the K. lactis kl killer plasmid. One fragment (Kla1) is 700 base pairs (bp) in length plasmids carrying it are mitotically unstable in both hosts. In K. lactis, this instability leads to colonies having a ‘nibbled’ phenotype when grown on selective media and appears to be the results of inefficient plasmid segregation. The other fragment of 1100 bp which was produced during the cloning procedure. Kla2 has been divided into the sub‐fragments Kla2A and Kla2B which have, respectively, ARS activity in K. lactis and S. Cerevisiar but not the other species. This indicates that these two closely elated yeasts have different sequence requrements for ARS activity. Kla2B contains a perfect match to the S. cerevisiae ARS consensus but Kla2A does not. Both Kla2A and Kla1 share a 10 bp sequence as the sole region of homology between them. This sequence, 5‘TCATAATATA3’, is tentatively offered as defining the ARS consensus sequence for K. lactis.
Orthogonal‐field‐alternation gel electrophoresis banding patterns of DNA from yeasts
Authors: De Jonge Peter , De Jongh Francien C. M. , Meijers Robert , Steensma H. Yde , Scheffers W. Alexander 
Published: May 2005

AbstractChromosomal DNAs from various yeast species were separated by orthogonal‐field‐alternation gel electrophoresis (OFAGE). To this end we developed a spheroplasting and lysis method to obtain intact DNA from both ascomycetous and basidiomycetous yeasts. The OFAGE banding patterns of 22 ascomycetous and four basidiomycetous yeast strains were compared. The strains represented species from the genera: Brettanomyces, Candida, Croococcus, Filobasidiella, Geotrichum, Hansenula, Kluyveromyces, Pachysolen, Pichia, Rhodosporidium, Rhodotorula, Saccharomyces, Saccharomycodes, Saccharomycopis, Schizosaccharomyces and Zygosaccharomyces. Variations occurred in the number of bands and their positions in the gel, not only among strains of different genera but also among species from the same genus and even between varieties of the same species. The ascomycetous yeasts, with the exeption of Saccharomyces cerevisiae, only showed one to five bands of DNA larger than 1000 kilobase pairs (kb) in general none smaller. The paterns of the four basidiomycetous yeasts revealed also a few large DNA bands but in addition one to six bands ranging in size from 500 to 1000 kb, with the exception of a single smaller chromosome in Rhodotorula mucilaginosa. From the OFAGE banding patterns of strains studied here it appears that in Saach. cerevisiae the partitioning of DNA over chromosomes in unique. But rather than the large number of chromosomes, the presence of four chromosomes with less than 500 kb of DNA is characteristic for Sacch. cerevisiae.
Analysis of DNA sequences homologous with the ARS core consensus in Saccharomyces cerevisiae
Authors: Bouton Amy H. , Stirling Vivianne B. , Smith M. Mitchell 
Published: May 2005

AbstractWe have previously identified an autonomously replicating segment (ARS) near the 3′ end of the histone H4 gene at the copy‐I H3‐H4 locus. We have now searched for additional autonomously replicating segments and sequences homologous with the ARS core consensus sequence near the copy‐II histone H4 gene and both of the histone H3 genes. No new ARS elements were identified by functional cloning assays. However, several matches to the ARS core consensus element were found within the DNA sequencs of the copy‐I and copy‐II genes. An exact match to the ARS core consensus was identified in the region downstream from the copy‐I histone H3 gene and a set of sequences with weak homology was also locatd within the copy‐II region. However, restriction fragments including these sequences did not demonstrate ARS activity on a plasmid in transformed cells.
Yeast flocculation: Kinetics and collision theory
Authors: Stratford M. , Keenan M. H. J. 
Published: May 2005

AbstractFlocculent yeast cells have an absolute requirement for mechanical energy input in order for flocculation to occur. Flocculation is arrested by cessation of energy input. The initial rate of flocculation increases as the square of the cell concentration. There is a minimum shaking speed to initiate flocculation and thereafter the initial rate of flocculation increases exponentially with the shaking speed. The minimum shaking speed for flocculation to occur increases with pH value. Activation energy for flocculation, derived from Arrhenius‐like plots, varies with pH value. We propose that activation energy is required to overcome mutual repulsion between charged yeast cells and allow flocculent bonds to be formed.
Mapping of the Saccharomyces cerevisiae CDC3, CDC25, and CDC42 genes to chromosome XII by chromosome blotting and tetrad analysis
Authors: Johnson Douglas I. , Jacobs Charles W. , Pringle John R. , Robinson Lucy C. , Carle Georges F. , Olson Maynard V. 
Published: May 2005

AbstractCDC3, CDC25 and CDC42 were localized to chromosome XII by hybridizing the cloned genes to Southern blots of chromosomes separated by orthogonal‐field‐alternation gel electrophoresis. Meiotic tetrad analyses further localized these genes to the region distal to the RDN1 locus on the right arm of the chromosome. The STE11 gene, which had previously been mapped to chromosome XII (Chaleff and Tatchell, 1985), was found to be tightly linked to ILV5. The data suggest a map order of CEN12‐RDN1‐CDC42‐(CDC25‐CDC3)‐(ILV5‐STE11)‐URA4. Certain oddities of the data set raise the possibility that there may be constraints on the patterns of recombination in this region of chromosome XII.
Possible gene interchange between plasmid and chromosome in yeast
Authors: Utatsu Ikuyo , Imura Toshiaki , Toh‐E Akio 
Published: May 2005

AbstractGenomic DNAs isolated from 420 yeast strains stocked in the Department of Fermentation Technology, Hiroshima university (HUT) were screened fro the presence of a plasmid sequence both as plasmid or in the chromosome. Five DNA samples gave rise to a positive hybridization signal wht 32P‐labelled Zygosaccharomyces plasmid pSR1 was used as a probe. Two among these contain hybridzing sequences as plasmids while the other three apparently were chromosomal. Two chromosomal DNA segments of HUT 7195 (Zygosaccharomyces spp.) which hybridized with pSR1 probe were cloned and sequenced. Both DNAs hybridized with a plasmid sequence covering the P gene of pSR1. One of hte tow segments contains a large open reading frame which can encode 410 amino acid residues. The deduced amino acid sequence is closely related with that of the P gene of pSR1. The present finding suggests that there was an interchange(s) of a gene between yeast plasmid(s) and chromosomes.
Karyotyping of yeast strains of several genera by field inversion gel electrophoresis
Authors: Johnston John R. , Contopoulou C. Rebecca , Mortimer Robert K. 
Published: May 2005

AbstractField inversion gel electrophoresis as been used to improve the resolution of the large chromosomes (>1000 kb) present in Saccharomyces kluyveri and in several genera of yeasts other than Saccharomyces cerevisiae, and thus establish more accurately the electrophoretic karyotype of these yeasts. Field inversion gel electrophoresis has also been used to demonstrate the presence of chromosome length polymorphisms in serveral of the yeasts studied. By Southern blotting techniques the greater degree of relatedness of S. Kluyveri and Kluyberomyces lactis to S. cerevisiae, as compared to that of the other genera of yeasts studied, has been established.
Substrate specificity of the phosphorylated fructose‐1,6‐bisphosphatase dephosphorylating protein phosphatase from Saccharomyces cerevisiae
Authors: Manhart Alexander , Holzer Helmut 
Published: May 2005

AbstractEnzymatic dephosphorylation of the phosphorylated forms of five different yeast enzymes has been studied: fructose‐1,6‐bisphosphatase, glycogen phosphorylase, neutral trehalase, NAD‐glutamate dehydrogenase and 6‐phosphofructo‐2‐kinase. Phosphorylated fructose‐1,6‐bisphosphatated 6‐phosphofructo‐2‐kinase were present in extracts of starved yeast cells which had been incubated for 10 min with glucose. Phosphorylated glycogen phosphorylase, neutral trehalase and NAD‐glutamate dehydrogenase were obtained by incubation of yeast extract with ATP, cycle AMP and Mg2+. After incubation with commercially available preparations of alkaline phosphatase, all five phosphorylated enzymes studied showed the changes in catalytic activity that would be expected as a consequence of dephosphorylation. The recently purified yeast enzyme which dephosphorylates phosphorylated fructose‐1,6‐bisophosphatase (Horn and Holzer (1987)) however, was found to be active only with the phosphorylated fructose‐1,6‐bisphosphatase, but not with the other four phosphorylated enzymes studied. By contrast, a crude extract from yeast showed dephosphorylating activity towards all five substrates. Substrate specificity with the five phosphorylated enzymes studied of different phosphoprotein phosphatases from yeast prepared by other is discussed.
Genetic control of chromosone stability in the yeast Saccharomyces cerevisiae
Authors: Kouprina N. Yu. , Pashina O. B. , Nikolaishwili N. T. , Tsouladze A. M. , Larionov V. L. 
Published: May 2005

AbstractWe have identified four new genetic loci: CHL2 (on chromosome XII) CHL3 (on chromosomes XII); CHL4 (on chrosomes IV), and CHL5 (on chromosomes IX), controlling mitotic transmission of yeast chromosomes. The frequency of loss of chromosomes is 10–100‐fold in chl5, chl2, chl3 and chl4 mutants than observed in wild‐type strains. The mutants also unstable maintenance of artifcial circular minichromosomes with various chromosomal replicators (ARS) and one of the concentrations loci (CEN3, CEN4, CEN5, or CEN6). The instability of minichrosomes in the chl5, chl2, and chl4 mutants id due to the loss of minichromosomes in mitosis (1 : 0 segregation). In the chl3 mutant the instability of artificial minichromosomes is due to nondisjunction (2 : 0 segregation). The CHL3 gene therfre appears to affect the segregation of chromosomes during cell division.
Metabolic responses of Saccharomyces cerevisiae CBS 8066 and Candida utilis CBS 621 upon transition from glucose limitation to glucose excess
Authors: Van Urk Hendrick , Mark Paul R. , Scheffers W. Alexander , Van Dijken Johannes P. 
Published: May 2005

AbstractWhen chemostat cultures of Saccharomyces cerevisiae CBS 8066 and Candida utilis CBS 621, grown under glucose limitation, were pulsed with excess glucose, both organisms initially exhibites similar rates of glucose and oxygen consumption. However, striking differences were apparent between the two yeasts with respect to the production of cell mass in the culture and metabolic excretion. Upon transition from glucose limitation excess, S. cerevisiae produced much ethanol but growth rate close to that under glucose limitation. C. utilis, on the other hand, produced little ethanol and immediately started to accumulated cell mass at a high rate. This high production rate of protein synthesis.Upon a glucose pulse both yeasts excreated pyuvate. In contrast to C. utilis. S. cerevisiae also excerted various tricarboxylic acid cycle intermediates, both under steady‐state conditions and after exposure to glucose excess, These results and those of theoritical calculations on ATP flows support the hypothesis that the ethanol production as a consequences of pyruvate accumulatiion in S. cerevisiae, occuring transition from glucose limitaion to glucose excess, is caused by a limited capacity of assimilatory pathways.
Cloning of CDC33: A gene essential for growth and sporulation which does not interfere with cAMP production in Saccharomyces cerevisiae
Authors: Verdier Jean‐Michel , Camonis Jacquesh H. , Jacquet Michel 
Published: May 2005

AbstractThe CDC33 gene of Saccharomyces cerevisiae belongs to the class II ‘START’ genes. Its product is required for the initiation of a new cell division cycle (Hartwell, 1974). Many results suggest that the cAMP signalling pathway is one of the major controlling elements of ‘START’. Components of this pathway are encoded by class II ‘START’ genes. The aim of the present study is to determine whether or not the CDC33 gene interferes with the cAMP signalling pathway. We report here the molecular cloning of the CDC33 gene by complementation of the cdc33‒1 thermosensitive mutant. The identity of the cloned gene is confirmed by site‐specific reintegration and segregation analysis. This gene is transcribed into a 900‐nucleotides mRNA and appears to be relatively abundant in the cell. We also show that the CDC33 gene product is essential for sporulation. cdc33‒1 mutant cells are able to enter into the resting state. The cAMP intracellular pool is not modified when the cdc33‒1 mutant is shifted to the restrictive temperature. The cdc33‒1 mutation is not suppressed by other known elements of the cAMP cascade. All these results suggest that the CDC33 ‘START’ gene does not interfere with the cAMP signalling pathway which controls cell division.
Mapping and characterizing a new DNA replication mutant in Saccharomyces cerevisiae
Authors: Eberly Susan L. , Sakai Akira , Sugino Akio 
Published: May 2005

AbstractA detailed characterization of the mak 1–3 mutation of Saccharomyces cerevisiae has been made possible by modifying its genetic background. The mak1–3 mutation, which confers temperature sensitivity for growth, was originally identified as one of four mak1 mutations (Wickner and Leibowitz, 1976). Mak1–1, 1–2 and 1–4 mutants are deficient in DNA topoisomerase I activity and thus have been renamed ‘top1’ (Thrash et al., 1984). Studies presented here show that the map position of MAK1–3 on chromosome XVI distinguishes it from TOP1 which maps on chromosome XV (Wickner and Leibowitz, 1976). An investigation of in vivo macromolecular synthesis in the mak1–3 mutant shows that it is deficient in DNA replication at the restrictive temperature. Experiments in which DNA synthesis was measured in synchronized cell populations indicate that the mak1–3 mutant is deficient in the initiation step of DNA synthesis. Furthermore, crude extracts from the mak1–3 mutant cells support temperature‐sensitive in vitro DNA synthesis on yeast chromosomal DNA replication origin containing plasmid pARS1, suggesting that the MAK1 gene product is directly required for in vitro DNA replication. The conclusion that mak1–3 is a newly identified DNA replication mutation is based on the observations that it (1) complements all DNA synthesis mutants examined, (2) maps to a previously undetected chromosomal location and (3) has a distinct terminal morphology. In light of these distinctions and of the role mak1–3 plays in DNA replication, it has been renamed ‘dnal’.
Kinetics of growth and glucose transport in glucose‐limited chemostat cultures of Saccharomyces cerevisiae CBS 8066
Authors: Postma Erik , Alexander Scheffers W. , Van Dijken Johannes P. 
Published: May 2005

AbstractThe glucose transport capacity of Saccharomyces cerevisiae CBS 8066 was studied in aerobic glucose‐limited chemostat cultures. Two different transport systems were encountered with affinity constants of 1 and 20 mM, respectively. The capacity of these carriers (Vmax) was dependent on the dilution rate and the residual glucose concentration in the culture. From the residual glucose concentration in the fermenter and the kinetic constants of glucose transport, their in situ contribution to glucose consumption was determined. The sum of these calculated in situ transport rates correlated well with the observed rate of glucose consumption of the culture.The growth kinetics of S. cerevisiae CBS 8066 in glucose‐limited cultures were rather perculiar. At low dilution rates, at which glucose was completely respired, the glucose concentration in the fermenter was constant at 110 μM, independent of the glucose concentration in the reservoir. At high dilution rates, characterized by the occurrence of both respiration and alcoholic fermentation, the residual substrate concentration followed Monod kinetics. In this case, however, the overall affinity constant was dependent on the reservoir glucose concentration.
Secretion and glycosylation of Clostridium thermocellum endoglucanase A encoded by the celA gene in Saccharomyces cerevisiae
Authors: Benitez J. , Silva A. , Vazquez R. , Noa M. D. , Hollenberg C. P. 
Published: May 2005

AbstractThe Clostridium thermocellum celA gene encoding endoglucanase A is expressed in Saccharomyces cerevisiae but the enzyme produced from the native celA gene is not secreted. After removal of the bacterial signal peptide‐coding sequence, the gene was fused to the promoter and prepro segment of the S. cerevisiae MFα1 gene. This construction directs secretion of active endoglucanase A into the culture medium when introduced in yeast on either replicating or integrating vectors. Secretion of endoglucanase A required growth of transformants on rich medium. The secreted enzyme is a 97 000 Da glycoprotein containing about half of its molecular weight as carbohydrate. This new gene fusion could facilitate further research on protein secretion in yeast by using a cellulase as a marker enzyme.
Yeast flocculation: Calcium specificity
Authors: Stratford Malcolm 
Published: May 2005

AbstractExpression of flocculation in yeast requires the presence of multi‐charged cations. Calcium ions fulfil this role over a broad pH range. At near neutral pH, magnesium and a variety of transition elements can induce flocculation. Calcium‐induced flocculation was competitively inhibited by excess sodium ions whereas magnesium‐induced flocculation was not competitively inhibited. Potassium and lithium ions caused similar inhibition but to a lesser extent. 45Ca effux from yeast cells was greatly increased by the external presence of buffer and cations. Inhibition of flocculation by chelating agents, EDTA or EGTA, was overcome by excess calcium ions. Flocculation could not be induced, under these conditions, by excess magnesium or transition‐element salts.It was concluded that yeast flocculation has a direct specific requirement for calcium ions. Other ions cause flocculation indirectly by effecting calcium ion leakage from cells, which is then able to initiate flocculation. Low calcium concentrations were susceptible to competitive inhibition by sodium ions present in most acidic buffers. In addition, citrate ions inhibited flocculation, probably by sequestration of leaked calcium. Flocculation by salts, other than calcium, was thus restricted to a neutral or high pH range.
Detection of specific RNA sequences in yeast by in situ colony hybridization
Authors: Inanov Ivan , Mironova Rumjana , Philipova Doranelly , Venkov Pencho 
Published: May 2005

AbstractRecently a convenient method for detection of specific RNA sequences in bacteria has been developed (Ivanov and Gigova, 1986) but the original protocol was inapplicable to microorganisms with a rigid cell wall. Here we report a modification of the RNA colony hybridization for use with yeast. The modified method includes the following consecutive procedures: (a) treatment of the yeast colonies on the membrane filter with 10% SDS at 65°C for 30 min; (b) treatment of the same filter with 3 × SSC, 10% formaldehyde at 65°C for 30 min; (c) hybridization with 32 P‐labelled oligonucleotide or (DNA) specific for the RNA sequence of interest. The intensity of the radioactive signals thus obtained is comparable with that of the E. colsi colonies.
Metabolic regulation in the yeast Hansenula polymorpha. Growth of dihydroxyacetone kinase/glycerol kinase‐negative mutants on mixtures of methanol and xylose in continuous cultures
Authors: De Koning W. , Weusthuis R. A. , Harder W. , Dijkhuizen L. 
Published: May 2005

AbstractThe physiological responses of Hansenula polymorpha wild‐type and mutant strains 17B (dihydroxyacetone kinase‐negative) and 17BG51 (dihydroxyacetone kinase‐ and glycerol kinase‐negative) to growth on mixtures of xylose and methanol in chemostats were investigated. Increasing methanol concentrations (0–110 mM) in the feed of the wild‐type culture resulted in increasing cell densities and a gradual switch towards methanol metabolism. At the lower methanol feed concentrations the mutant cultures used methanol and xylose to completion and changes in enzyme patterns comparable to the wild type were observed. This was not reflected in significant changes in cell densities. Instead, formaldehyde assimilation resulted in dihydroxyacetone (DHA) production, which was proportional to the amount of methanol added. At intermediate methanol concentration the cultures showed a strong variation in DHA levels and cell densities. Further increased in the methanol feed concentrations resulted in a drop in DHA accumulation rates, repression of alcohol oxidase synthesis and accumulation of residual methanol. The phenomena were studied in more detail in transition experiments and with gradients of methanol. The results indicate that xylulose‐5‐phosphate (Xu5P) generated in xylose metabolism served as acceptor molecule for formaldehyde assimilation by the peroxisomal enzyme DHA synthase. Accumulation of DHA in the mutant cultures, however, further diminished the availability of carbon for growth. The data suggest that with increasing methanol concentrations Xu5P eventually became growth rate limiting. This resulted in an unstable situation but wash‐out of the culture did not occur to a significant extent. Instead, DHA accumulation ceased and cell densities, and enzymes specifically involved in xylose metabolism increase, indicating that the organism resumed its xylose metabolism. The molecular mechanisms controlling the partitioning of Xu5P over xylose (pentose phosphate pathway) and methanol (peroxisome) metabolism under these conditions remain to be elucidated.
Cloning and sequencing of the ornithine carbamoyltransferase gene from Pachysolen tannophilus
Authors: Skrzypek M. , Borsuk P. , Maleszka R. 
Published: May 2005

AbstractA fragment of DNA from a yeast Pachysolen tannophilus, bearing the ornithine carbamoyltransferase gene (OCTase, EC 2.1.3.3) has been cloned from a genomic library by functional complementation of the Escherichia coli OCT‐negative mutant. The gene was located within the cloned segment of DNA and its coding sequence identified by DNA sequencing. This has indicated that P. tannophilus OCT gene encodes a 347 amino acid polypeptide, which shows 60% identity to the homologous Saccharomyces cerevisiae protein. The amino acid composition of its N‐terminus indicates that this protein is translocated across the mitochondrial membrane. The gene can be expressed in E. coli as well as in S. cerevisiae. Comparison with other OCTases confirms a high degree of conservation among these proteins.