Search results for "Ribonuclease H"
showing 10 items of 12 documents
CRISPR-mediated strand displacement logic circuits with toehold-free DNA
2021
DNA nanotechnology, and DNA computing in particular, has grown extensively over the past decade to end with a variety of functional stable structures and dynamic circuits. However, the use as designer elements of regular DNA pieces, perfectly complementary double strands, has remained elusive. Here, we report the exploitation of CRISPR-Cas systems to engineer logic circuits based on isothermal strand displacement that perform with toehold-free double-stranded DNA. We designed and implemented molecular converters for signal detection and amplification, showing good interoperability between enzymatic and nonenzymatic processes. Overall, these results contribute to enlarge the repertoire of su…
ICTV Virus Taxonomy Profile: Pseudoviridae
2021
Pseudoviridae is a family of reverse-transcribing viruses with long terminal repeats (LTRs) belonging to the order Ortervirales. Pseudoviruses are commonly found integrated in the genomes of diverse plants, fungi and animals and are broadly known as Ty1/Copia LTR retrotransposons. Inside the cell, they form icosahedral virus particles, but unlike most other viruses, do not have an extracellular phase. This is a summary of the ICTV Report on the family Pseudoviridae, which is available at ictv.global/report/pseudoviridae.
RNase H1 and H2 Are Differentially Regulated to Process RNA-DNA Hybrids
2019
Summary: RNA-DNA hybrids are tightly regulated to ensure genome integrity. The RNase H enzymes RNase H1 and H2 contribute to chromosomal stability through the removal of RNA-DNA hybrids. Loss of RNase H2 function is implicated in human diseases of the nervous system and cancer. To better understand RNA-DNA hybrid dynamics, we focused on elucidating the regulation of the RNase H enzymes themselves. Using yeast as a model system, we demonstrate that RNase H1 and H2 are controlled in different manners. RNase H2 has strict cell cycle requirements, in that it has an essential function in G2/M for both R-loop processing and ribonucleotide excision repair. RNase H1, however, can function independe…
RNase H2 Loss in Murine Astrocytes Results in Cellular Defects Reminiscent of Nucleic Acid-Mediated Autoinflammation
2018
Aicardi-Goutières syndrome (AGS) is a rare early onset childhood encephalopathy caused by persistent neuroinflammation of autoimmune origin. AGS is a genetic disorder and >50% of affected individuals bear hypomorphic mutations in ribonuclease H2 (RNase H2). All available RNase H2 mouse models so far fail to mimic the prominent CNS involvement seen in AGS. To establish a mouse model recapitulating the human disease, we deleted RNase H2 specifically in the brain, the most severely affected organ in AGS. Although RNase H2δGFAPmice lacked the nuclease in astrocytes and a majority of neurons, no disease signs were apparent in these animals. We additionally confirmed these results…
Associations of LPL and APOC3 gene polymorphisms on plasma lipids in a mediterranean population: Interaction with tobacco smoking and the APOE locus
2002
We conducted a cross-sectional study in a Spanish population (n = 1,029) to investigate associations between the LPL and APOC3 gene loci (LPL-HindIII, LPL-S447X, and APOC3-SstI) and plasma lipid levels and their interaction with APOE polymorphisms and smoking. Carriers of the H− or the X447 allele had higher levels of HDL cholesterol (HDL-C), and lower levels of TG, after adjustment for age, body mass index, alcohol, smoking, exercise, and education (P < 0.01). The APOC3 polymorphism presented additive effects to the LPL variants on TG and HDL-C levels in men, and on TG in women. The most and the least favorable haplotype combinations were H−/X447/S1 and H+/S447/S2, respectively. These comb…
Nucleotide sequence of a Trichophyton mentagrophytes HindIII mitochondrial DNA fragment containing at RNA gene cluster
1993
A 0.85-kb HindIII mitochondrial DNA fragment of the dermatophytic fungus Trichophyton mentagrophytes has been sequenced. The fragment contains eight complete genes which corresponds to a tRNA gene cluster. From 5′ to 3′, the sequenced genes code for tRNAthr, tRNAglu, tRNAval, tRNAmet1, tRNAmet3, tRNAleu, tRNAala, and tRNAphe. This tRNA gene cluster is located downstream of the larger ribosomal RNA gene. The particularities ofthe sequenced genes and their comparison with other fungal tRNA mitochondrial genes are reported.
A new method for the mapping of 5' ends of RNAs.
2008
In this article, we describe a new procedure to map 5' ends of RNAs. The procedure consists in the use of specific RNase H digestion of a hybrid formed by the RNA and a complementary DNA oligonucleotide. Northern blot hybridization of the resulting RNA fragment allows an accurate measurement of its length. Although we generally use this procedure as a control of previously performed primer extension analyses, the absence of nonspecific bands, which often occur in primer extensions on RNA templates with extended secondary structures, suggests that our method may be preferable when these difficult templates are analyzed.
Molecular and physiological consequences of faulty eukaryotic ribonucleotide excision repair
2019
Abstract The duplication of the eukaryotic genome is an intricate process that has to be tightly safe‐guarded. One of the most frequently occurring errors during DNA synthesis is the mis‐insertion of a ribonucleotide instead of a deoxyribonucleotide. Ribonucleotide excision repair (RER) is initiated by RNase H2 and results in error‐free removal of such mis‐incorporated ribonucleotides. If left unrepaired, DNA‐embedded ribonucleotides result in a variety of alterations within chromosomal DNA, which ultimately lead to genome instability. Here, we review how genomic ribonucleotides lead to chromosomal aberrations and discuss how the tight regulation of RER timing may be important for preventin…
High-resolution genotyping of Campylobacter strains isolated from poultry and humans with amplified fragment length polymorphism fingerprinting.
1999
ABSTRACT For epidemiological studies of Campylobacter infections, molecular typing methods that can differentiate campylobacters at the strain level are needed. In this study we used a recently developed genotyping method, amplified fragment length polymorphism (AFLP), which is based on selective amplification of restriction fragments of chromosomal DNA, for genetic typing of Campylobacter jejuni and Campylobacter coli strains derived from humans and poultry. We developed an automated AFLP fingerprinting method in which restriction endonucleases Hin dIII and Hha I were used in combination with one set of selective PCR primers. This method resulted in evenly distributed band patterns for amp…
Isolation of Vibrio vulnificus Serovar E from Aquatic Habitats in Taiwan
1999
ABSTRACT The existence of strains of Vibrio vulnificus serovar E that are avirulent for eels is reported in this work. These isolates were recovered from water and oysters and differed from eel virulent strains in (i) fermentation and utilization of mannitol, (ii) ribotyping after Hin dIII digestion, and (iii) susceptibility to eel serum. Lipopolysaccharide of these strains lacked the highest molecular weight immunoreactive bands, which are probably involved in serum resistance.