1,721,018 research outputs found
Ordered processing of the polygenic transcripts from a mitochondrial transfer-RNA gene cluster in K. lactis.
No full textIn Saccharomyces cerevisiae, transcription of the mitochondrial genome starts at multiple initiation sites and is followed by the processing of multigenic transcripts at the 5' and 3' termini of tRNA sequences and in some intergenic regions. We have used a comparative approach to investigate the structure and function of the latter processing sites. We present here an analysis of the transcripts of a cluster of tRNA genes from the mitochondrial genome of Kluyveromyces lactis. The gene order of this cluster is the same as that of the cluster in S. cerevisiae but the sequence of the intergenic regions is different. A detailed analysis of transcripts has been performed using S1 mapping and primer extension techniques. The results can be summarized as follows: (1) transcription of the cluster very probably starts at initiation sites having the nonanucleotide sequence TTATAAGTA (which acts as a promoter in S. cerevisiae) and yields polygenic transcripts; (2) processing of these transcripts seems to occur through an ordered pathway of endonucleolytic events in which some tRNA sequences are preferentially excised and some endonucleolytic cuts occur more readily than others; (3) in two intergenic regions, strong signals indicate the existence of processing events. The sequences around these sites are similar in sequence and localization to S. cerevisiae intergenic processing sites, indicating a possible functional importance in maintaining a conserved order of tRNA genes in different species of yeasts
La riattivazione del complesso Ex Salesiani di Faenza tra vocazione originaria ed energie contemporanee
No full textIl riuso del complesso Ex Salesiani di Faenza presentato come caso emblematico di rigenerazione urbana della provincia di Ravenn
La riattivazione del complesso Ex Salesiani di Faenza tra vocazione originaria ed energie contemporanee
No full textIl riuso del complesso Ex Salesiani di Faenza presentato come caso emblematico di rigenerazione urbana della provincia di Ravenn
Mutazioni ts nei geni per i tRNA mitocondriali in S.cerevisiae quali strumenti per lo studio di interazioni nucleo citoplasmatiche
No full text
Mitochondrial protein synthesizing machinery in Saccharomyces cerevisiae grown in different metabolic conditions.
No full textAnalysis of transcripts of the major cluster of tRNA genes in the mitochondrial genome of S. cerevisiae
No full textThe transcripts of a 6Kbp region of the mitochondrial genome of S. cerevisiae, localized in the 21S rRNA-OXI1 span and including 12 tRNA genes (from tRNA(thr) to tRNA(ala)) and several G+C clusters, have been studied by analysis of in vitro capped primary transcripts and by fine mapping of the 5' ends of transcripts. The study was performed in the w.t. strain D273-10B and in several rho- mutants retaining different, partially overlapping portions of the studied region; the mutants accumulate incompletely-processed precursors of tRNAs due to the absence of the tRNA synthesis locus. Results show the presence in the region of four sites at which initiation occurs at a consensus nonanucleotide ATTATAAGTA (or a minor variant of the same); however different initiation sites are used in different strains, and several differences as compared to initiation in vitro can also be observed. Termini arising by processing are often localized at AATATAA or AATATATTTT sequences localized immediately adjacent to a G+C cluster or a tRNA sequence
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