scholarly journals Interactions between RNA polymerase and the core recognition element are a determinant of transcription start site selection

2016 ◽  
Vol 113 (21) ◽  
pp. E2899-E2905 ◽  
Author(s):  
Irina O. Vvedenskaya ◽  
Hanif Vahedian-Movahed ◽  
Yuanchao Zhang ◽  
Deanne M. Taylor ◽  
Richard H. Ebright ◽  
...  

During transcription initiation, RNA polymerase (RNAP) holoenzyme unwinds ∼13 bp of promoter DNA, forming an RNAP-promoter open complex (RPo) containing a single-stranded transcription bubble, and selects a template-strand nucleotide to serve as the transcription start site (TSS). In RPo, RNAP core enzyme makes sequence-specific protein–DNA interactions with the downstream part of the nontemplate strand of the transcription bubble (“core recognition element,” CRE). Here, we investigated whether sequence-specific RNAP–CRE interactions affect TSS selection. To do this, we used two next-generation sequencing-based approaches to compare the TSS profile of WT RNAP to that of an RNAP derivative defective in sequence-specific RNAP–CRE interactions. First, using massively systematic transcript end readout, MASTER, we assessed effects of RNAP–CRE interactions on TSS selection in vitro and in vivo for a library of 47 (∼16,000) consensus promoters containing different TSS region sequences, and we observed that the TSS profile of the RNAP derivative defective in RNAP–CRE interactions differed from that of WT RNAP, in a manner that correlated with the presence of consensus CRE sequences in the TSS region. Second, using 5′ merodiploid native-elongating-transcript sequencing, 5′ mNET-seq, we assessed effects of RNAP–CRE interactions at natural promoters in Escherichia coli, and we identified 39 promoters at which RNAP–CRE interactions determine TSS selection. Our findings establish RNAP–CRE interactions are a functional determinant of TSS selection. We propose that RNAP–CRE interactions modulate the position of the downstream end of the transcription bubble in RPo, and thereby modulate TSS selection, which involves transcription bubble expansion or transcription bubble contraction (scrunching or antiscrunching).

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Libing Yu ◽  
Jared T Winkelman ◽  
Chirangini Pukhrambam ◽  
Terence R Strick ◽  
Bryce E Nickels ◽  
...  

During transcription initiation, RNA polymerase (RNAP) binds to promoter DNA, unwinds promoter DNA to form an RNAP-promoter open complex (RPo) containing a single-stranded ‘transcription bubble,’ and selects a transcription start site (TSS). TSS selection occurs at different positions within the promoter region, depending on promoter sequence and initiating-substrate concentration. Variability in TSS selection has been proposed to involve DNA ‘scrunching’ and ‘anti-scrunching,’ the hallmarks of which are: (i) forward and reverse movement of the RNAP leading edge, but not trailing edge, relative to DNA, and (ii) expansion and contraction of the transcription bubble. Here, using in vitro and in vivo protein-DNA photocrosslinking and single-molecule nanomanipulation, we show bacterial TSS selection exhibits both hallmarks of scrunching and anti-scrunching, and we define energetics of scrunching and anti-scrunching. The results establish the mechanism of TSS selection by bacterial RNAP and suggest a general mechanism for TSS selection by bacterial, archaeal, and eukaryotic RNAP.


2017 ◽  
Author(s):  
Libing Yu ◽  
Jared T. Winkelman ◽  
Chirangini Pukhrambam ◽  
Terence R. Strick ◽  
Bryce E. Nickels ◽  
...  

SUMMARYDuring transcription initiation, RNA polymerase (RNAP) binds to promoter DNA, unwinds promoter DNA to form an RNAP-promoter open complex (RPo) containing a single-stranded "transcription bubble," and selects a transcription start site (TSS). TSS selection occurs at different positions within the promoter region, depending on promoter sequence and initiating-substrate concentration. Variability in TSS selection has been proposed to involve DNA "scrunching" and "antiscrunching," the hallmarks of which are: (i) forward and reverse movement of the RNAP leading edge, but not trailing edge, relative to DNA, and (ii) expansion and contraction of the transcription bubble. Here, using in vitro and in vivo protein-DNA photocrosslinking and single-molecule nanomanipulation, we show bacterial TSS selection exhibits both hallmarks of scrunching and anti-scrunching, and we define energetics of scrunching and anti-scrunching. The results establish the mechanism of TSS selection by bacterial RNAP and suggest a general mechanism for TSS selection by bacterial, archaeal, and eukaryotic RNAP.


2020 ◽  
Author(s):  
Zhe Sun ◽  
Alexander Yakhnin ◽  
Peter C. FitzGerald ◽  
Carl E. Mclntosh ◽  
Mikhail Kashlev

ABSTRACTPromoter-proximal pausing regulates expression of many eukaryotic genes and serves as checkpoints for assembly of elongation/splicing machinery. Little is known how broadly the pausing is employed in transcriptional regulation in bacteria. We applied NET-seq combined with RNase I footprinting for genome-wide analysis of σ70-dependent transcription pauses in Escherichia coli. Many E. coli genes appear to contain clusters of strong backtracked pauses at 10-20-bp distance from the transcription start site caused by retention of σ70 subunit in RNA polymerase. The pauses in 10-15-bp register of the promoter are dictated by binding of σ70 to canonical −10 element, 6-7 nt spacer and “YR+1Y” motif centered at transcription start site all characteristic for strong E. coli promoters. The promoters for the pauses in 16-20-bp register contain an additional −10-like sequence positioned on the same face of the DNA duplex as the original −10 element suggesting that σ70 hopping was responsible for these pauses. Our in vitro analysis reveals that RNA polymerase backtracking and DNA scrunching are involved in these pauses that are relieved by Gre transcript cleavage factors. The genes coding for transcription factors are enriched in these pauses suggesting that σ70 and Gre proteins regulate transcription in response to changing environmental cues.


1994 ◽  
Vol 14 (5) ◽  
pp. 3094-3107
Author(s):  
J C Kennell ◽  
H Wang ◽  
A M Lambowitz

The Mauriceville plasmid and the closely related Varkud plasmid of Neurospora spp. are retroelements that propagate in mitochondria. Replication appears to occur by a novel mechanism in which a monomer-length plasmid transcript having a 3' tRNA-like structure ending in CCA is reverse transcribed to give a full-length minus-strand cDNA beginning at or near the 3' end of the RNA. Here, we show that the plasmids are transcribed in vitro by the Neurospora mitochondrial RNA polymerase, with the major in vitro transcription start site approximately 260 bp upstream of the 5' end of the plasmid transcript. The location of the transcription start site suggests that the monomer-length transcripts are generated by transcription around the plasmid combined with a site-specific RNA cleavage after the 3'-CCA sequence. The 5' ends of minus-strand cDNAs in ribonucleoprotein particles were analyzed to obtain insight into the mechanism of initiation of reverse transcription in vivo. A major class of minus-strand cDNAs begins opposite C2 of the 3'-CCA sequence, the same site used for de novo initiation of cDNA synthesis by the plasmid reverse transcriptase in vitro. A second class of minus-strand cDNAs begins with putative primer sequences that correspond to cDNA copies of the plasmid or mitochondrial transcripts. These findings are consistent with the possibility that the plasmid reverse transcriptase initiates minus-strand cDNA synthesis in vivo both by de novo initiation and by a novel template-switching mechanism in which the 3' OH of a previously synthesized cDNA is used to prime the synthesis of a new minus-strand cDNA directly at the 3' end of the plasmid transcript.


Gene ◽  
2013 ◽  
Vol 512 (2) ◽  
pp. 286-293 ◽  
Author(s):  
Yasushi Yukawa ◽  
Kazuhito Akama ◽  
Kanta Noguchi ◽  
Masaaki Komiya ◽  
Masahiro Sugiura

2020 ◽  
Vol 3 (10) ◽  
pp. e202000762
Author(s):  
Oscar D Villarreal ◽  
Sofiane Y Mersaoui ◽  
Zhenbao Yu ◽  
Jean-Yves Masson ◽  
Stéphane Richard

DDX5, XRN2, and PRMT5 have been shown to resolve DNA/RNA hybrids (R-loops) at RNA polymerase II transcription termination sites at few genomic loci. Herein, we perform genome-wide R-loop mapping using classical DNA/RNA immunoprecipitation and high-throughput sequencing (DRIP-seq) of loci regulated by DDX5, XRN2, and PRMT5. We observed hundreds to thousands of R-loop gains and losses at transcribed loci in DDX5-, XRN2-, and PRMT5-deficient U2OS cells. R-loop gains were characteristic of highly transcribed genes located at gene-rich regions, whereas R-loop losses were observed in low-density gene areas. DDX5, XRN2, and PRMT5 shared many R-loop gain loci at transcription termination sites, consistent with their coordinated role in RNA polymerase II transcription termination. DDX5-depleted cells had unique R-loop gain peaks near the transcription start site that did not overlap with those of siXRN2 and siPRMT5 cells, suggesting a role for DDX5 in transcription initiation independent of XRN2 and PRMT5. Moreover, we observed that the accumulated R-loops at certain loci in siDDX5, siXRN2, and siPRMT5 cells near the transcription start site of genes led to antisense intergenic transcription. Our findings define unique and shared roles of DDX5, XRN2, and PRMT5 in DNA/RNA hybrid regulation.


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