scholarly journals Palindromic Sequences of the Markov Spectrum

2019 ◽  
Vol 106 (3-4) ◽  
pp. 457-467
Author(s):  
M. van Son
Keyword(s):  
Markov Spectrum ◽  
Palindromic Sequences

scholarly journals Interactions of the Streptococcus pneumoniae Toxin-Antitoxin RelBE Proteins with Their Target DNA

2021 ◽  
Vol 9 (4) ◽  
pp. 851
Author(s):  
Inmaculada Moreno-Córdoba ◽  
Wai-Ting Chan ◽  
Concha Nieto ◽  
Manuel Espinosa
Keyword(s):  
Streptococcus Pneumoniae ◽  
Self Regulation ◽  
Mrna Translation ◽  
Dna Supercoiling ◽  
Bacterial Toxin ◽  
Type Ii ◽  
Cellular Functions ◽  
Dna Backbone ◽  
Different Strains ◽  
Palindromic Sequences

Type II bacterial toxin-antitoxin (TA) systems are found in most bacteria, archaea, and mobile genetic elements. TAs are usually found as a bi-cistronic operon composed of an unstable antitoxin and a stable toxin that targets crucial cellular functions like DNA supercoiling, cell-wall synthesis or mRNA translation. The type II RelBE system encoded by the pathogen Streptococcus pneumoniae is highly conserved among different strains and participates in biofilm formation and response to oxidative stress. Here, we have analyzed the participation of the RelB antitoxin and the RelB:RelE protein complex in the self-regulation of the pneumococcal relBE operon. RelB acted as a weak repressor, whereas RelE performed the role of a co-repressor. By DNA footprinting experiments, we show that the proteins bind to a region that encompasses two palindromic sequences that are located around the −10 sequences of the single promoter that directs the synthesis of the relBE mRNA. High-resolution footprinting assays showed the distribution of bases whose deoxyriboses are protected by the bound proteins, demonstrating that RelB and RelB:RelE contacted the DNA backbone on one face of the DNA helix and that these interactions extended beyond the palindromic sequences. Our findings suggest that the binding of the RelBE proteins to its DNA target would lead to direct inhibition of the binding of the host RNA polymerase to the relBE promoter.

scholarly journals A 160-bp Palindrome Is a Rad50·Rad32-Dependent Mitotic Recombination Hotspot inSchizosaccharomyces pombe

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 461-468 ◽  
Author(s):  
Joseph A Farah ◽  
Edgar Hartsuiker ◽  
Ken-ichi Mizuno ◽  
Kunihiro Ohta ◽  
Gerald R Smith
Keyword(s):  
Secondary Structure ◽  
Schizosaccharomyces Pombe ◽  
Inverted Repeat ◽  
Mitotic Recombination ◽  
Genome Integrity ◽  
Recombination Hotspot ◽  
Nuclease Domain ◽  
Palindromic Sequences

AbstractPalindromic sequences can form hairpin and cruciform structures that pose a threat to genome integrity. We found that a 160-bp palindrome (an inverted repeat of 80 bp) conferred a mitotic recombination hotspot relative to a control nonpalindromic sequence when inserted into the ade6 gene of Schizosaccharomyces pombe. The hotspot activity of the palindrome, but not the basal level of recombination, was abolished by a rad50 deletion, by a rad50S “separation of function” mutation, or by a rad32-D25A mutation in the nuclease domain of the Rad32 protein, an Mre11 homolog. We propose that upon extrusion of the palindrome the Rad50·Rad32 nuclease complex recognizes and cleaves the secondary structure thus formed and generates a recombinogenic break in the DNA.

Markov spectrum near Freiman's isolated points in M ∖ L

2019 ◽  
Vol 194 ◽  
pp. 390-408 ◽  
Author(s):  
Carlos Matheus ◽  
Carlos Gustavo Moreira
Keyword(s):  
Isolated Points ◽  
Markov Spectrum

scholarly journals Palindromic sequence-targeted (PST) PCR: a rapid and efficient method for high-throughput gene characterization and genome walking

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ruslan Kalendar ◽  
Alexandr V. Shustov ◽  
Mervi M. Seppänen ◽  
Alan H. Schulman ◽  
Frederick L. Stoddard
Keyword(s):  
Thermal Cycling ◽  
Annealing Temperature ◽  
Phleum Pratense ◽  
Genome Walking ◽  
Palindromic Sequence ◽  
Linear Amplification ◽  
Gene Characterization ◽  
Intron 1 ◽  
Thermal Cycling Profile ◽  
Palindromic Sequences

AbstractGenome walking (GW) refers to the capture and sequencing of unknown regions in a long DNA molecule that are adjacent to a region with a known sequence. A novel PCR-based method, palindromic sequence-targeted PCR (PST-PCR), was developed. PST-PCR is based on a distinctive design of walking primers and special thermal cycling conditions. The walking primers (PST primers) match palindromic sequences (PST sites) that are randomly distributed in natural DNA. The PST primers have palindromic sequences at their 3′-ends. Upstream of the palindromes there is a degenerate sequence (8–12 nucleotides long); defined adapters are present at the 5′-termini. The thermal cycling profile has a linear amplification phase and an exponential amplification phase differing in annealing temperature. Changing the annealing temperature to switch the amplification phases at a defined cycle controls the balance between sensitivity and specificity. In contrast to traditional genome walking methods, PST-PCR is rapid (two to three hours to produce GW fragments) as it uses only one or two PCR rounds. Using PST-PCR, previously unknown regions (the promoter and intron 1) of the VRN1 gene of Timothy-grass (Phleum pratense L.) were captured for sequencing. In our experience, PST-PCR had higher throughput and greater convenience in comparison to other GW methods.

scholarly journals Automata for DNA Splicing Languages with Palindromic and Non-Palindromic Restriction Enzymes using Grammars

MATEMATIKA ◽  
2019 ◽  
Vol 35 (4) ◽  
pp. 1-14
Author(s):  
Wan Heng Fong ◽  
Nurul Izzaty Ismail ◽  
Nor Haniza Sarmin
Keyword(s):  
Dna Sequences ◽  
Formal Language ◽  
Restriction Enzymes ◽  
Language Theory ◽  
Dna Assembly ◽  
Dna Molecules ◽  
Splicing Systems ◽  
Transition Graphs ◽  
Palindromic Sequences ◽  
Dna Splicing

In DNA splicing system, DNA molecules are cut and recombined with the presence of restriction enzymes and a ligase. The splicing system is analyzed via formal language theory where the molecules resulting from the splicing system generate a language which is called a splicing language. In nature, DNA molecules can be read in two ways; forward and backward. A sequence of string that reads the same forward and backward is known as a palindrome. Palindromic and non-palindromic sequences can also be recognized in restriction enzymes. Research on splicing languages from DNA splicing systems with palindromic and non-palindromic restriction enzymes have been done previously. This research is motivated by the problem of DNA assembly to read millions of long DNA sequences where the concepts of automata and grammars are applied in DNA splicing systems to simplify the assembly in short-read sequences. The splicing languages generated from DNA splicing systems with palindromic and nonpalindromic restriction enzymes are deduced from the grammars which are visualised as automata diagrams, and presented by transition graphs where transition labels represent the language of DNA molecules resulting from the respective DNA splicing systems.

scholarly journals Cloning and Analysis of the Telomere and Terminal Inverted Repeat of the Linear Chromosome of Streptomyces griseus

2002 ◽  
Vol 184 (12) ◽  
pp. 3411-3415 ◽  
Author(s):  
Kohei Goshi ◽  
Tetsuya Uchida ◽  
Alexander Lezhava ◽  
Masayuki Yamasaki ◽  
Keiichiro Hiratsu ◽  
...  
Keyword(s):  
Inverted Repeat ◽  
Streptomyces Griseus ◽  
Open Reading Frames ◽  
Terminal Inverted Repeat ◽  
Loop Structure ◽  
Hairpin Loop ◽  
Cloning And Sequencing ◽  
Linear Chromosome ◽  
Palindromic Sequences ◽  
Reading Frames

ABSTRACT Cloning and sequencing of the telomere of Streptomyces griseus revealed five palindromic sequences in the terminal 116 nucleotides, all of which can make a hairpin loop structure. However, the end sequence cannot form the foldback secondary structure that is common in Streptomyces telomeres and is suggested to be necessary for terminal replication. Both inside ends of the terminal inverted repeat (TIR) were also cloned and sequenced. The results confirmed the size of the TIR to be 24 kb and identified two almost identical open reading frames that might have been involved in the formation of the TIR.

Eigentime identity of the weighted (m,n)-flower networks

2020 ◽  
Vol 34 (18) ◽  
pp. 2050159
Author(s):  
Changxi Dai ◽  
Meifeng Dai ◽  
Tingting Ju ◽  
Xiangmei Song ◽  
Yu Sun ◽  
...  
Keyword(s):  
Random Walks ◽  
Characteristic Polynomial ◽  
Network Size ◽  
Weight Factor ◽  
Laplacian Eigenvalues ◽  
Weighted Networks ◽  
Expected Time ◽  
Leading Term ◽  
Analytic Expression ◽  
Markov Spectrum

The eigentime identity for random walks on the weighted networks is the expected time for a walker going from a node to another node. Eigentime identity can be studied by the sum of reciprocals of all nonzero Laplacian eigenvalues on the weighted networks. In this paper, we study the weighted [Formula: see text]-flower networks with the weight factor [Formula: see text]. We divide the set of the nonzero Laplacian eigenvalues into three subsets according to the obtained characteristic polynomial. Then we obtain the analytic expression of the eigentime identity [Formula: see text] of the weighted [Formula: see text]-flower networks by using the characteristic polynomial of Laplacian and recurrent structure of Markov spectrum. We take [Formula: see text], [Formula: see text] as example, and show that the leading term of the eigentime identity on the weighted [Formula: see text]-flower networks obey superlinearly, linearly with the network size.

scholarly journals Genomic Instability Signature of Palindromic Non-Coding Somatic Mutations in Bladder Cancer

Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2882
Author(s):  
Sophie Vacher ◽  
Voreak Suybeng ◽  
Elodie Girard ◽  
Julien Masliah Planchon ◽  
Grégory Thomson ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Cancer Patients ◽  
Genomic Instability ◽  
Somatic Mutations ◽  
Bladder Tumors ◽  
Protein Coding ◽  
Core Motif ◽  
Expression Levels ◽  
Mutational Hotspots ◽  
Palindromic Sequences

Numerous pan-genomic studies identified alterations in protein-coding genes and signaling pathways involved in bladder carcinogenesis, while non-coding somatic alterations remain weakly explored. The goal of this study was to identify clinical biomarkers in non-coding regions for bladder cancer patients. We have previously identified in bladder tumors two non-coding mutational hotspots occurring at high frequencies (≥30%). These mutations are located close to the GPR126 and PLEKHS1 genes, at the guanine or the cytosine of a TGAACA core motif flanked, on both sides, by a stretch of palindromic sequences. Here, we hypothesize that such a pattern of recurrent non-coding mutations could be a signature of somatic genomic instability specifically involved in bladder cancer. We analyzed 26 additional mutable non-coding sites with the same core motif in a cohort of 103 bladder cancers composed of 44 NMIBC cases and 59 MIBC cases using high-resolution melting (HRM) and Sanger sequencing. Five bladder cancers were additionally analyzed for protein-coding gene mutations using a targeted NGS panel composed of 571 genes. Expression levels of three members of the APOBEC3 family genes were assessed using real-time quantitative RT-PCR. Non-coding somatic mutations were observed for at least one TGAACA core motif locus in 62.1% (64/103) of bladder tumor samples. These non-coding mutations co-occurred in the bladder tumors but were absent in prostate tumor, HPV-positive Head and Neck Squamous Cell Carcinoma, and high microsatellite instability (MSI-H) colorectal tumor series. This signature of palindromic non-coding somatic mutations, specific to bladder tumors, was not associated with patients’ outcome and was more frequent in females. Interestingly, this signature was associated with high tumor mutational burden (TMB) and high expression levels of APOBEC3B and interferon inducible genes. We identified a new type of somatic genomic instability targeting the TGAACA core motif loci flanked by palindromic sequences in bladder cancer. This mutational signature is a promising candidate clinical biomarker for the early detection of relapse and a major low-cost alternative to the TMB to monitor the response to immunotherapy for bladder cancer patients.

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