Dimeric transfer RNA precursors in S. pombe

Mao, Jen-i; Schmidt, Otto; Söll, Dieter

doi:10.1016/0092-8674(80)90488-2

Cited by 93 publications

(65 citation statements)

References 24 publications

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“…In S. cerevisiae and S. pombe, the most frequent T run lengths are 6 and 7, and (as already mentioned) there is no single terminator shorter than T 5 . Remarkably, the tDNA terminators in fission yeast tend to be ϳ1 nt shorter than in S. cerevisiae, in agreement with a previous analysis showing 2 The only exceptions were represented by dimeric tDNAs, in which the upstream tDNA unit has no termination signal (45,58 that S. cerevisiae Pol III requires slightly longer T runs than the fission yeast enzyme in order to terminate efficiently (3). The T-run length distribution in mammals is completely different: T 4 is the most frequent tDNA terminator, and terminators longer than T 5 are rare.…”

Section: Oligo(dt) Termination Signals In Different Eukaryoticsupporting

confidence: 73%

Sequence Context Effects on Oligo(dT) Termination Signal Recognition by Saccharomyces cerevisiae RNA Polymerase III

Braglia

Percudani

Dieci

2005

Journal of Biological Chemistry

103

112

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Eukaryotic RNA polymerase (Pol) III terminates transcription at short runs of T residues in the coding DNA strand. By genomic analysis, we found that T 5 and T 4 are the shortest Pol III termination signals in yeasts and mammals, respectively, and that, at variance with yeast, oligo(dT) terminators longer than T 5 are very rare in mammals. In Saccharomyces cerevisiae, the strength of T 5 as a terminator was found to be largely influenced by both the upstream and the downstream sequence context. In particular, the CT sequence, which is naturally present downstream of T 5 in the 3-flank of some tDNAs, was found to act as a terminator-weakening element that facilitates translocation by reducing Pol III pausing at T 5 . In contrast, tDNA transcription termination was highly efficient when T 5 was followed by an A or G residue. Surprisingly, however, when a terminationproficient T 5 signal was taken out from the tDNA context and placed downstream of a fragment of the SCR1 gene, its termination activity was compromised, both in vitro and in vivo. Even the T 6 sequence, acting as a strong terminator in tRNA gene contexts, was unexpectedly weak within the SNR52 transcription unit, where it naturally occurs. The observed sequence context effects reflect intrinsic recognition properties of Pol III, because they were still observed in a simplified in vitro transcription system only consisting of purified RNA polymerase and template DNA. Our findings strengthen the notion that termination signal recognition by Pol III is influenced in a complex way by the region surrounding the T cluster and suggest that read-through transcription beyond T clusters might play a significant role in the biogenesis of class III gene products.Eukaryotic RNA polymerase (Pol) 1 III is unique among DNAdependent RNA polymerases in recognizing a simple run of T residues on the coding strand as a termination signal, in the apparent absence of accessory factors. The minimal signal thought to be sufficient to provoke Pol III termination varies among different eukaryotes. T 4 suffices for termination by Xenopus and human Pol III (1, 2), T 4 /T 5 for Schizosaccharomyces pombe Pol III (3), and T 5 /T 6 for Saccharomyces cerevisiae Pol III (4). Pol III termination within T clusters is generally heterogeneous and progressive (5), and termination efficiency tends to increase with the length of the T run (4). Mechanistically, Pol III termination involves extensive pausing, dictated by the T cluster itself (5, 6). Even during elongation, the addition of three UMP residues in succession is particularly slow (5). Pol III pausing at T clusters sets cycles of hydrolytic RNA chain retraction (7). Both pausing and the associated hydrolytic RNA cleavage are affected by mutations in the C160, C128, and C11 subunits of yeast Pol III (7-9). In the case of C128 and C11, the same mutations have also been shown to affect the termination properties of Pol III, thus suggesting a functional interplay between hydrolytic RNA cleavage and transcription termination (9, 10). The t...

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Section: Oligo(dt) Termination Signals In Different Eukaryoticsupporting

confidence: 73%

Sequence Context Effects on Oligo(dT) Termination Signal Recognition by Saccharomyces cerevisiae RNA Polymerase III

Braglia

Percudani

Dieci

2005

Journal of Biological Chemistry

103

112

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“…The yield of the 5'-terminal tRNA Asp fragment pTCCGp (marked in fig.3b) was equimolar with other unique tRNA Asp products, further evidence for complete RNase P processing of this RNA. The presence of AU, AUU and AUUU in low yield on the fingerprint ( fig.3b and table 1) is consistent with a small proportion of the tRNA Asp in the sample having 2-4 extra 3' nucleotides relative to RNA C. These results, obtained with a crude nuclear extract from the rna82 mutant, reveal that transcripts of yeast tRNA gene pairs are processed by a mechanism slightly more complicated than indicated by previous studies [9][10][11][12][13]. The data support the earlier conclusion that a single endonucleolytic cleavage (P1, fig.2) generates pretRNA Arg species bearing all 10 nucleotides of the intergenic spacer.…”

Section: Resultssupporting

confidence: 53%

Processing of transcripts of a dimeric tRNA gene in yeast uses the nuclease responsible for maturation of the 3′ termini upon 5 S and 37 S precursor rRNAs

Piper

Stråby

1989

FEBS Letters

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The rna82 mutation of Saccharomyces cerevisiae inactivates an RNA processing activity responsible for maturation of 3'-terminal sequences upon 5 S and 37 S ribosomal RNA precursors. This study describes a difference in the processing of transcripts of an S. cerevisiae dimeric tRNA gene (tRNA^rLtRNA~p) in RNA polymerase III in vitro transcription extracts prepared from rna82 and wild-type cells. The mutant extract accumulated additional processing intermediates containing tRNAArg sequences as compared to the extract from wild-type cells. The structure of these intermediates revealed a defect in removal of the 10 nucleotides left 3' to the tRNA^rg sequence by the RNase P cleavage immediately 5' to tRNA ^~p. This is the first demonstration of a mutational defect affecting maturation of 3' sequences upon a eukaryotic tRNA precursor.tRNA precursor; Nuclease deficiency; Sequence maturation, Y-; (S. cerevisiae)

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“…However, none were found to read through the strong termination sequence (CTTTTC) in intron C. The transcripts which terminate within Ic (Fig. 4 (16)(17)(18). Downstream genes initiate transcription only after removal of the upstream tRNA gene sequence (18).…”

Section: Cell-free Transcriptionmentioning

confidence: 99%

“…First, unlike most repetitive DNA, many of the rGH repeats occur in a tandem arrangement. This may be of particular interest in terms of expression, since in the cases studied to date in which multiple Pol III promoters occur naturally as tandemly arranged tRNA genes, Pol III transcription is initiated only with the first (i.e., the most 5') gene (16)(17)(18). Secondly, sequences of one of these repeat elements have been found in certain rat genes expressed uniquely in the brain and also comprise the major structure of a 160 nucleotide (nt) neuralspecific RNA (3,(9)(10)(11).…”

mentioning

confidence: 99%

Transcription of two classes of rat growth hormone gene-associated repetitive DNA: differences in activity and effects of tandem repeat structure

et al. 1984

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The rat growth hormone (rGH) gene contains two classes of repetitive DNA arranged as clusters within intron B and the 3' flanking region. The major family is equivalent to the CHO type 2 DNA. The second ("truncated repeat", TR) is a truncated version of the first and occurs in certain neural-specific transcripts and genes ("identifier" elements, ID). Here we report, using the HeLa cell-free transcription assay, that RNA polymerase III (Pol III) efficiently initiates at internal promoters within a tandem array of rGH gene repetitive DNA monomers and results in a novel organization of overlapping Class III transcription units. Transcription competition studies revealed that the rat type 2 structures share Pol III transcription factors with a tRNA gene, a human Alu repeat, and a mutant VAl gene. Also, the rGH type 2 but not the TR DNA efficiently promotes Pol III initiation, yet other TR members, which differ only in flanking DNA, are transcribed. Thus, the rGH gene is strikingly enriched with 10 repetitive DNA monomers; multimeric type 2 elements are actively transcribed; rGH-TR sequences are expressed only as part of larger transcripts promoted by type 2 DNA; and, type 2 DNA uses tRNA gene transcription factors. These studies show that flanking sequences, promoter organization and factor competition may all affect rat repetitive DNA expression. INTRODUCTIONThe major component of mammalian short-length, middle-repetitive DNA is

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Dimeric transfer RNA precursors in S. pombe

Cited by 93 publications

References 24 publications

Sequence Context Effects on Oligo(dT) Termination Signal Recognition by Saccharomyces cerevisiae RNA Polymerase III

Sequence Context Effects on Oligo(dT) Termination Signal Recognition by Saccharomyces cerevisiae RNA Polymerase III

Processing of transcripts of a dimeric tRNA gene in yeast uses the nuclease responsible for maturation of the 3′ termini upon 5 S and 37 S precursor rRNAs

Transcription of two classes of rat growth hormone gene-associated repetitive DNA: differences in activity and effects of tandem repeat structure

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