scholarly journals Rho-dependent transcription termination. Characterization of the requirement for cytidine in the nascent transcript.

1991 ◽  
Vol 266 (35) ◽  
pp. 24140-24148 ◽  
Author(s):  
C.M. Hart ◽  
J.W. Roberts
Keyword(s):  
Transcription Termination ◽  
Nascent Transcript

scholarly journals Transcription-termination-mediated immunity and its prevention in bacteriophage SfV of Shigella flexneri

2007 ◽  
Vol 88 (11) ◽  
pp. 3187-3197 ◽  
Author(s):  
Fleur Roberts ◽  
Gwen E. Allison ◽  
Naresh K. Verma
Keyword(s):  
Essential Role ◽  
Transcription Termination ◽  
Shigella Flexneri ◽  
Temperate Phage ◽  
The Novel ◽  
Subsequent Infection

The temperate phage SfV encodes the genes responsible for the serotype conversion of Shigella flexneri strains from serotype Y to 5a. Bacteriophages often encode proteins that prevent subsequent infection by homologous phages; the mechanism by which this is accomplished is referred to as superinfection immunity. The serotype conversion mediated following lysogenization of SfV is one such mechanism. Another mechanism is the putative λ-like CI protein within SfV. This study reports the characterization of a third superinfection mechanism, transcription termination, in SfV. The presence of a small immunity-mediating RNA molecule, called CI RNA, and its essential role in the establishment of immunity, is shown. The novel role of the gene orf77, located immediately downstream from the transcription termination region, in inhibiting the establishment of CI RNA-mediated immunity is also presented.

scholarly journals Crystallization and preliminary X-ray characterization of the eukaryotic replication terminator Reb1–Ter DNA complex

2015 ◽  
Vol 71 (4) ◽  
pp. 414-418 ◽  
Author(s):  
Rahul Jaiswal ◽  
Samarendra K. Singh ◽  
Deepak Bastia ◽  
Carlos R. Escalante
Keyword(s):  
Replication Fork ◽  
Structural Information ◽  
Transcription Termination ◽  
Replication Forks ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Naturally Occurring ◽  
Dna Complex

The Reb1 protein fromSchizosaccharomyces pombeis a member of a family of proteins that control programmed replication termination and/or transcription termination in eukaryotic cells. These events occur at naturally occurring replication fork barriers (RFBs), where Reb1 binds to termination (Ter) DNA sites and coordinates the polar arrest of replication forks and transcription approaching in opposite directions. The Reb1 DNA-binding and replication-termination domain was expressed inEscherichia coli, purified and crystallized in complex with a 26-mer DNA Ter site. Batch crystallization under oil was required to produce crystals of good quality for data collection. Crystals grew in space groupP21, with unit-cell parametersa= 68.9,b= 162.9,c= 71.1 Å, β = 94.7°. The crystals diffracted to a resolution of 3.0 Å. The crystals were mosaic and required two or three cycles of annealing. This study is the first to yield structural information about this important family of proteins and will provide insights into the mechanism of replication and transcription termination.

scholarly journals Single-molecule characterization of extrinsic transcription termination by Sen1 helicase

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
S. Wang ◽  
Z. Han ◽  
D. Libri ◽  
O. Porrua ◽  
T. R. Strick
Keyword(s):  
Single Molecule ◽  
Transcription Termination

Kinetics of mRNA polyadenylation and its relation to transcription termination in eukaryotes

2000 ◽  
Vol 28 (5) ◽  
pp. A461-A461
Author(s):  
Amer Jamil ◽  
Harold G. Martinson
Keyword(s):  
Transcription Termination ◽  
Rnase Protection Assay ◽  
Nascent Transcript ◽  
Rnase Protection ◽  
Multistep Process ◽  
Eukaryotic Mrnas ◽  
Cleavage And Polyadenylation ◽  
A Site ◽  
Antisense Element

Processing of most eukaryotic mRNAs includes and polyadenylation of the nascent transcript. Until now there has been no method for the reliable measurement of these processes in vivo. Therefore, in the present work a new technique was developed for measuring precisely the rate of cleavage and polyadenylation in vivo. The method uses a cis-antisense element targeted to an upstream poly (A) signal. Duplex formation of the antisense element with the poly (A) signal region prevents polyadenylation. In a series of expression vector constructs the antisense element was moved increasing distances downstream of its target poly (A) site, reasoning that if it takes the polymerase longer to reach the antisense element, polyadenylation would have more time to occur. Using this method the half time for commitment to cleavage and polyadenylation at the SV40 early poly (A) site and SPA (synthetic poly A site) was found to be 5 seconds. It was found that strong sites (SV 40 late poly (A) site) were processed faster. Commitment to cleavage and polyadenylation was found to be a multistep process. The expression results were confirmed with the help of RNase protection assay. Relationship between polyadenylation and transcription termination was also studied by using G-free assay and found to be positively correlated. Present data support looping moded suggesting some communication exists between polyadenylation complex and RNA pol. II for transcription termination.

scholarly journals Characterization of Transcription Termination-Associated RNAs: New Insights into their Biogenesis, Tailing, and Expression in Primary Tumors

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Ilaria Laudadio ◽  
Sara Formichetti ◽  
Silvia Gioiosa ◽  
Filippos Klironomos ◽  
Nikolaus Rajewsky ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Transcription Termination ◽  
Dna Integrity ◽  
Transcription Start ◽  
Cycle Progression ◽  
Primary Tumors ◽  
Transcription Start Sites ◽  
Generation Sequencing ◽  
Comprehensive Study

Next-generation sequencing has uncovered novel classes of small RNAs (sRNAs) in eukaryotes, in addition to the well-known miRNAs, siRNAs, and piRNAs. In particular, sRNA species arise from transcription start sites (TSSs) and the transcription termination sites (TTSs) of genes. However, a detailed characterization of these new classes of sRNAs is still lacking. Here, we present a comprehensive study of sRNAs derived from TTSs of expressed genes (TTSa-RNAs) in human cell lines and primary tissues. Taking advantage of sRNA-sequencing, we show that TTSa-RNAs are present in the nuclei of human cells, are loaded onto both AGO1 and AGO2, and their biogenesis does not require DICER and AGO2 endonucleolytic activity. TTSa-RNAs display a strong bias against a G residue in the first position at 5′ end, a known feature of AGO-bound sRNAs, and a peculiar oligoA tail at 3′ end. AGO-bound TTSa-RNAs derive from genes involved in cell cycle progression regulation and DNA integrity checkpoints. Finally, we provide evidence that TTSa-RNAs can be detected by sRNA-Seq in primary human tissue, and their expression increases in tumor samples as compared to nontumor tissues, suggesting that in the future, TTSa-RNAs might be explored as biomarker for diagnosis or prognosis of human malignancies.

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