ISSN:0749-503X    

DOI:10.1002/yea.320111602

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320111603

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractYeast chromosome ends are similar in structure and function to chromosome ends in most, if not all, eukaryotic organisms. There is a G‐rich terminal repeat at the ends which is maintained by telomerase. In addition to the classical functions of protecting the end from degradation and end‐to‐end fusions, and completing replication, yeast telomeres have several interesting properties including: non‐nucleosomal chromatin structure; transcriptional position effect variegation for genes with adjacent telomeres; nuclear peripheral localization; apparent physical clustering; non‐random recombinational interactions. A number of genes have been identified that are involved in modifying one or more of these properties. These include genes involved in general DNA metabolism, chromatin structure and telomere maintenance. Adjacent to the terminal repeat is a mosaic of middle repetitive elements that exhibit a great deal of polymorphism both between individual strains and among different chromosome ends. Much of the sequence redundancy in the yeast genome is found in the sub‐telomeric regions (within the last 25 kb of each end). The sub‐telomeric regions are generally low in gene density, low in transcription, low in recombination, and they are late replicating. The only element which appears to be shared by all chromosome ends is part of the previously defined X element containing an ARS consensus. Most of the ‘core’ X elements also contain an Abf1p binding site and a URS1‐like element, which may have consequences for the chromatin structure, nuclear architecture and transcription of native telomeres. Possible functions of sub‐telomeric repeats include: fillers for increasing chromosome size to some minimum threshold level necessary for chromosome stability; barrier against transcriptional silencing; a suitable region for adaptive amplification of genes; secondary mechanism of telomere maintenance via recombination when telomera

ISSN:0749-503X    

DOI:10.1002/yea.320111604

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractAll eukaryotic cells contain a wide variety of proteins embedded in the plasma and internal membranes, which ensure transmembrane solute transport. It is now established that a large proportion of these transport proteins can be grouped into families apparently conserved throughout organisms. This article presents the data of anin silicioanalysis aimed at establishing a preliminary classification of membrane transport proteins inSaccharomyces cerevisiae. This analysis was conducted at a time when about 65% of all yeast genes were available in public databases. In addition to ∼60 transport proteins whose function was at least partially known, ∼100 deduced protein sequences of unknown function display significant sequence similarity to membrane transport proteins characterized in yeast and/or other organisms. While some protein families have been well characterized by classical genetic experimental approaches, others have largely if not totally escaped characterization. The proteins revealed by thisin silicioanalysis also include a putative K+channel, proteins similar to aquaporins of plant and animal origin, proteins similar to Na+‐solute symporters, a protein very similar to electroneural cation‐chloride co‐transporters, and a putative Na+‐H+antiporter. A new research area is anticipated: the functional analysis of many transport proteins whose existence was revealed by genome

ISSN:0749-503X    

DOI:10.1002/yea.320111605

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractAcademic studies and traditional breeding of yeasts depend upon their sporulation lifestyle. The strains used have been specially selected to sporulate readily and to mate producing new yeast types. Unfortunately brewing yeast strains do not behave in this way. They sporulate poorly, any spores which are formed are usually non‐viable and any haploid strains produced are invariably non‐maters. Only in recent years, with the development of recombinant‐DNA techniques, has the specific breeding of new brewing yeast strains become widespread. Strains have been produced with the ability to ferment a wider range of carbohydrates, with altered flocculation properties and which produce beers with modified flavours. Many have been tested on the pilot scale and one, an amylolytic brewing yeast, has received approval for commercia

ISSN:0749-503X    

DOI:10.1002/yea.320111606

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractPost‐transcriptional processing of precursor‐ribosomal RNA comprises a complex pathway of endonucleolytic cleavages, exonucleolytic digestion and covalent modifications. The general order of the various processing steps is well conserved in eukaryotic cells, but the underlying mechanisms are largely unknown. Recent analysis of pre‐rRNA processing, mainly in the yeastSaccharomyces cerevisiae, has significantly improved our understanding of this important cellular activity. Here we will review the data that have led to our current picture of yeast pre‐rRNA pro

ISSN:0749-503X    

DOI:10.1002/yea.320111607

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320111608

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

Abstract[URE3] is a non‐Mendelian genetic element that mimics recessive mutations in the chromosomalURE2gene making cells derepressed for nitrogen catabolic enzymes. [PSI] is a non‐Mendelian enhancer of readthrough of translational termination similar in its effects to some mutations in the chromosomalSUP35gene. Three lines of evidence led to the proposal75that both [URE3] and [PSI]are prions, infectious proteins analogous to the scrapie agent mediating transmissible spongiform encephalopathies of mammals. (1) Both [PSI] and [URE3]are reversibly curable. (2) [PSI] propagation requiresSUP35and [URE3] propagation requiresURE2with recessive chromosomal mutants having the same phenotypes as the presence of the respective dominant non‐Mendelian element. (3) Overproduction of Sup35p and Ure2p increases the frequency of cells acquiring [PSI] or [URE3], respect

ISSN:0749-503X    

DOI:10.1002/yea.320111609

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320111601

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY