Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Inverted Repeat Sequences”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

The structure of the pseudorabies virus genome at the end of the inverted repeat sequences proximal to the junction with the short unique region.

The complete nucleotide sequence is presented of the 2 x 67 kbp BamHI-EcoRV portion of the BamHI 10 fragment of the pseudorabies virus (PRV) genome (strain Ka) containing sequences upstream of the previously reported protein kinase gene, and completing the sequence of this 4008 bp fragment. It is predicted to contain a gene designated RSp40, homologous to gene US1 of herpes simplex virus type 1 (HSV-1), with the potential to encode a protein of 364 amino acids. Analysis of PRV mRNA synthesized in the presence and absence of cycloheximide indicated that, in contrast to its HSV-1 homologue, the PRV gene RSp40 does not specify an immediate-early mRNA. Between the RSp40 gene and the protein kinase gene are two reiterated sequences: one containing 11 tandem copies of a 35 nucleotide sequence and the other containing nine tandem copies of a 10 nucleotide sequence. The BamHI 10 and the BamHI 12 fragments of PRV contain the junctions between the short unique (US) and short repeat (RS) regions of the PRV genome. The nucleotide sequence of that portion of the BamHI 12 fragment containing US sequences was determined so that, by comparison with the nucleotide sequence of the BamHI 10 fragment, the junction between the US and RS regions could be defined. In BamHI 10 this was found to be at a point between the two reiterated sequences (which are in the RS region) and the protein kinase gene (which is in the US region). The organization of this region of the PRV genome is compared to that of other alphaherpesviruses.

Amino Acid Sequence↗

ADR1-mediated regulation of ADH2 requires an inverted repeat sequence.

DNA sequence analysis of wild-type and mutant ADH2 loci suggested that two unusual features 5' of the promoter, a 22-base-pair perfect dyad sequence and a (dA)20 tract, were important for regulation of this gene (D. W. Russell, M. Smith, D. Cox, V. M. Williamson, and E. T. Young, Nature [London] 304:652-654, 1983). Oligonucleotide-directed mutagenesis was used to construct ADH2 genes lacking the 22-base-pair dyad or the (dA)20 tract (V.-L. Chan and M. Smith, Nucleic Acids Res. 12:2407-2419, 1984). These mutant genes and other ADH2 deletions constructed by BAL 31 endonuclease digestion were studied after replacing the wild-type chromosomal locus with the altered alleles by the technique of gene transplacement (T. L. Orr-Weaver, J. W. Szostak, and R. S. Rothstein, Proc. Natl. Acad. Sci. USA 78:6354-6358, 1981), using canavanine resistance as the selectable marker. Deletions lacking the dyad failed to derepress normally and did not respond to mutations at the ADR1 locus, which encodes a protein necessary to activate ADH2. Deletions of the (dA)20 tract did not have a detectable phenotype. A small deletion located just 3' to the (dA)20 tract (between positions -164 and -146) had a low amount of ADR1-dependent transcription during repressed growth conditions, indicating that the regulatory protein encoded by ADR1 is present in a potentially active form during repression and that alterations of a DNA sequence in the promoter region can unmask its latent activity.

Alcohol Dehydrogenase↗

Deletions and duplication in internal inverted repeat sequence of long region/unique sequence of long region (IRL/UL) of herpes simplex virus type-1 (HSV-1) genome are not evidently associated with intracranial and foot-pad pathogenicity in mouse model.

The biological properties of three deletion variants (1704, 1705 and 1706) of herpes simplex virus type-1 (HSV-1) strain 17 syn+, were studied by establishing a base line pathogenicity of nine individual plaques from the parental 17 syn+ elite stock. Restriction enzyme analysis of deoxyribonucleic acid (DNA) from each of the nine plaque stocks and intracranial inoculation into three weeks old BALB/c mice showed no difference in the size of fragments and distribution of the sites or their 50% lethal dose (LD50) values [plaque forming units (pfu)/mouse] as compared to the parental 17 syn+ stock. Inoculation of the variants into three weeks old BALB/c mice showed that 1705 was not different in pathogenicity from the wild type following intracranial and footpad inoculations. On the other hand variants 1704 and 1706, when compared to the wild type virus were less virulent on intracranial inoculation i.e. the difference in LD50 values was approximately one log and two logs respectively and both the variants failed to kill any of the animals following footpad inoculation even at the dose of 1 x 10(7) pfu/mouse. During in vivo replication experiment in the peripheral nervous system of mice, 1704 and 1706 grew very poorly.

Amino Acid Sequence↗

Cytological localization of inverted repeated DNA sequences in Vicia faba.

Inverted repeated DNA sequences have been isolated from sheared Vicia faba DNA by hydroxylapatite column chromatography, treated with nuclease S1, tritiated by the nick translation method and hybridized in situ on squashes of Vicia faba root tips. Silver grains appear grouped in a rather limited portion of interphase nuclei and form a sort of band across them. The central regions of metaphase chromosomes are preferentially labeled, labeling being excluded from telomeres, centromeres and secondary constrictions. These results are briefly discussed in relation to those obtained in other species and the functional significance of inverted repeats.

DNA↗

Mitochondrial plasmid DNAs of broad bean: nucleotide sequences, complex secondary structures, and transcription.

Three circular plasmid DNA molecules of 1704, 1695 and 1476 nucleotide pairs from broad bean mitochondria (mt-plasmids 1-3) have been sequenced. Within a highly homologous segment of mt-plasmid 1 and 2 are found a series of six directly repeated, inverted repeat sequences, separated by unique sequences. Mt-plasmid 3 contains a series of four inverted repeat sequences, unrelated to the inverted repeat sequences of mt-plasmids 1 and 2. Two RNA molecules of about 440 and 320 nucleotides that are complementary to mt-plasmid 2 were detected. Mapping of 5' and 3' termini of these complementary RNA molecules indicated that all transcription from mt-plasmid 2 occurs within a 441 nucleotide region of the molecule. Evidence for transcription of mt-plasmids 1 and 3 was not found.

Base Sequence↗

Molecular analysis of the replication origin of the Lactococcus lactis plasmid pCJ305.

The replication origin region, ori, of the Lactococcus lactis subsp. lactis plasmid pCI305 contains three-and-one-half directly repeated 22-bp sequences and two inverted repeat sequences, IR1 and IR2. These inverted repeat sequences overlap the promoter of the repB gene, which encodes a protein (RepB) essential for plasmid replication. Gel retardation assays, using lactococcal crude cell extracts in which RepB was overproduced, were used to demonstrate that the replication protein interacts with DNA sequences within the origin region. IR1 was identified as a RepB binding site. The -35 region of the repB promoter is contained within the loop of the potential stem-loop structure of IR1, suggesting autoregulation of repB. The pCI305 RepB failed to interact with DNA sequences within the minimal replicons of nine other members of the pCI305 family of plasmids and it was concluded that this DNA-protein interaction was replicon specific. In vivo studies were performed to determine the role of the three-and-one-half copies of the 22-bp sequences. When this sequence was provided in trans on a compatible vector, it resulted in the loss of pCI305 from the cell population (incompatibility).

Bacterial Proteins↗

Mapping of inverted repeated DNA sequences within the genome of simian virus 40.

Single-stranded, linear DNA of simian virus 40 (SV40) created by denaturing the endonuclease EcoRI- or Hpa II-generated, linear, double-stranded products from form I DNA of SV40 was analyzed for regions of inverted repeated sequences by visualization with the electron microscope. Six hairpin loops were found at positions 0.11-0.30 (two loops forming a "rabbit ears" structure), 0.47-0.52, 0.63-0.68, 0.70-0.76, and 0.90-0.96. The nucleotide sequences within all of these inverted repeats may be related since the looped regions can crosshybridize with one another and, thus, the SV40 genome may contain regions of interspersed repeated and unique sequences. The map positions of the 3' and 5' ends of the early and late messenger RNAs, as determined by others, lie within regions of inverted repeated sequences. Previously recorded recombination events that occurred either within the SV40 genome or between SV40 DNA and other genomes have apparently occurred frequently at positions of inverted repeated sequences within the SV40 DNA.

Base Sequence↗

Characterization of the DNA of the hamster papovavirus. III. Mapping of inverted repeated DNA sequences within the viral genome.

Sequences with 2-fold axis of symmetry (inverted repeated sequences) have been detected and mapped on the hamster papovavirus (HaPV) genome by their ability to form secondary structures like hairpins or stem-loops on single-stranded HaPV DNA. DNA regions with secondary structure were visualized by electron microscopy and mapped according to the physical map of HaPV. Eleven positions containing inverted repeats could be determined. The nucleotide sequence within all of these inverted repeats may be related since these regions can crosshybridize with each other. The possible functions of these sequences within the HaPV genome are discussed with respect to conditions found for genomes like those from SV40 and polyoma virus to get first indications for the localization of DNA regions representing the origin and termination of replication of HaPV DNA.

Animals↗

PCR-based genotyping of Mycobacterium tuberculosis with new GC-rich repeated sequences and IS6110 inverted repeats used as primers.

In the present study we attempted to develop a PCR-based epidemiological tool for the differentiation of Mycobacterium tuberculosis isolates. Use of the designed primers Mtb1 (5'-CCG-GCG-GGG-CCG-GCG-G) and Mtb2 (5'-CGG-CGG-CAA-CGG-CGG-C) targeting frequently repeated 16-bp sequences in combination with primers sited at the inverted repeats flanking IS6110 allowed differentiation of M. tuberculosis isolates.

DNA Fingerprinting↗

Inverted repeat nucleotide sequences in the genomes of Marek disease virus and the herpesvirus of the turkey.

The DNAs of two herpesvirus, the oncogenic Marek disease virus and the serologically related herpesvirus of the turkey, were studied by electron microscopy. On the basis of fold-back molecules observed in single-stranded DNA from both viruses, structures have been derived from the overall nucleotide sequence arrangement in their genomes. Although differing in molecular weight, the genomes of Marek disease virus and turkey herpesvirus are both constructed according to the same plan--two regions of unique nucleotide sequence, each enclosed by inverted repeat sequence. The genome structure of these viruses therefore closely resembles that of herpes simplex virus rather than the biologically more similar herpesvirus Epstein--Barr virus, H. saimiri, and H. ateles.

Animals↗

Mutational analysis of the R64 oriT region: requirement for precise location of the NikA-binding sequence.

Conjugative DNA transfer of IncI1 plasmid R64 is initiated by the introduction of a site- and strand-specific nick into the origin of transfer (oriT). In R64 oriT, 17-bp (repeat A and B) and 8-bp inverted-repeat sequences with mismatches are located 8 bp away from the nick site. The nicking is mediated by R64 NikA and NikB proteins. To analyze the functional organization of the R64 oriT region, various deletion, insertion, and substitution mutations were introduced into a 92-bp minimal R64 oriT sequence and their effects on oriT function were investigated. This detailed analysis confirms our previous prediction that the R64 oriT region consists of an oriT core sequence and additional sequences necessary for full oriT activity. The oriT core sequence consists of the repeat A sequence, which is recognized by R64 NikA protein, and the nick region sequence, which is conserved among various origins of transfer and is most probably recognized by NikB protein. The oriT core sequence is sufficient for NikAB-mediated oriT-specific nicking. Furthermore, it was shown that the repeat A sequence is essential for localization to a precise position relative to the nick site for oriT function. This seems to be required for the formation of a functional ternary complex consisting of NikA and NikB proteins and oriT DNA. The repeat B sequence and 8-bp inverted repeat sequences are suggested to be required for the termination of DNA transfer.

Bacterial Proteins↗

Analysis of the subtelomeric regions of macronuclear gene-sized DNA molecules of the hypotrichous ciliate Stylonychia lemnae: implications for the DNA fragmentation process during macronuclear development?

The subtelomeric regions of macronuclear gene-sized DNA molecules from Stylonychia lemnae were analyzed. The results obtained indicate that these regions show a highly ordered and common sequence organization: Immediately adjacent to the telomeric sequence a short inverted repeat sequence is found, followed by another 7-9 bp inverted repeat sequence at approximately position 40. A 10 bp consensus sequence found in the subtelomeric regions of all gene-sized DNA molecules is found at approximately position 60 and in addition at about the same position palindromic sequences showing no homology to each other are localized. The biological significance of this sequence organization is discussed.

Animals↗

Chloroplast mRNA 3' end processing requires a nuclear-encoded RNA-binding protein.

The protein coding regions of plastid mRNAs in higher plants are generally flanked by 3' inverted repeat sequences. In spinach chloroplast mRNAs, these inverted repeat sequences can fold into stem-loop structures and serve as signals for the correct processing of the mature mRNA 3' ends. The inverted repeat sequences are also required to stabilize 5' upstream mRNA segments, and interact with chloroplast protein in vitro. To dissect the molecular components involved in chloroplast mRNA 3' end processing and stability, a spinach chloroplast protein extract containing mRNA 3' end processing activity was fractionated by FPLC and RNA affinity chromatography. The purified fraction consisted of several proteins and was capable of processing the 3' ends of the psbA, rbcL, petD and rps14 mRNAs. This protein fraction was enriched for a 28 kd RNA-binding protein (28RNP) which interacts with both the precursor and mature 3' ends of the four mRNAs. Using specific antibodies to this protein, the poly(A) RNA-derived cDNA for the 28RNP was cloned and sequenced. The predicted amino acid sequence for the 28RNP reveals two conserved RNA-binding domains, including the consensus sequences RNP-CS1 and CS2, and a novel acidic and glycine-rich N-terminal domain. The accumulation of the nuclear-encoded 28RNP mRNA and protein are developmentally regulated in spinach cotyledons, leaves, root and stem, and are enhanced during light-dependent chloroplast development. The general correlation between accumulation of the 28RNP and plastid mRNA during development, together with the result that depletion of the 28RNP from the chloroplast protein extract interferes with the correct 3' end processing of several chloroplast mRNAs, suggests that the 28RNP is required for plastid mRNA 3' end processing and/or stability.

Amino Acid Sequence↗

Genetic analysis of transfer-related regions of the vancomycin resistance Enterococcus conjugative plasmid pHTbeta: identification of oriT and a putative relaxase gene.

The pHT plasmids pHTalpha (65.9 kbp), pHTbeta (63.7 kbp), and pHTgamma (66.5 kbp) are highly conjugative pheromone-independent pMG1-like plasmids that carry Tn1546-like transposons encoding vancomycin resistance. pHTbeta is the prototype plasmid, and the pHTalpha and pHTgamma plasmids are derivatives of the insertion into pHTbeta of an IS232-like (2.2 kbp) element and a group II intron (2.8 kbp), respectively. The complete nucleotide sequence of the pHTbeta plasmid was determined and, with the exception of the Tn1546-like insertion (10,851 bp), was found to be 52,890 bp. Sixty-one open reading frames (ORFs) having the same transcript orientation were identified. A homology search revealed that 22 of the pHTbeta (pHT) plasmid ORFs showed similarities to the ORFs identified on the pXO2 plasmid (96.2 kbp), which is the virulence plasmid essential for capsule formation by Bacillus anthracis; however, the functions of most of the ORFs remain unknown. Most other ORFs did not show any significant homology to reported genes for which functions have been analyzed. To investigate the highly efficient transfer mechanism of the pHT plasmid, mutations with 174 unique insertions of transposon Tn917-lac insertion mutants of pHTbeta were obtained. Of the 174 derivatives, 92 showed decrease or loss in transfer frequency, and 74 showed normal transfer frequency and LacZ expression. Eight derivatives showed normal transfer and no LacZ expression. Inserts within the 174 derivatives were mapped to 124 different sites on pHTbeta. The Tn917-lac insertions which resulted in altered transfer frequency mapped to three separate regions designated I, II, and III, which were separated by segments in which insertions of Tn917-lac did not affect transfer. There was no region homologous to the previously reported oriT sequences in the pHT plasmid. The oriT was cloned by selection for the ability to mobilize the vector plasmid pAM401. The oriT region resided in a noncoding region (192 bp) between ORF31 and ORF32 and contained three direct repeat sequences and two inverted repeat sequences. ORF34, encoding a 506-amino-acid protein which was located downstream of the oriT region, contains the three conserved motifs (I to III) of the DNA relaxase/nickase of mobile plasmids. The transfer abilities of the Tn917-lac-insertion mutants of ORF34 or a mutant of ORF34 with an in-frame motif III deletion were completely abolished. The sequence of the oriT region and the deduced relaxase/nickase protein of ORF34 showed no significant similarity to the oriT and relaxase/nickase of other conjugative plasmids, respectively. The putative relaxase/nickase protein of ORF34 could be classified as a new member of the MOB(MG) family.

Amino Acid Motifs↗

Effect of base composition at the center of inverted repeated DNA sequences on cruciform transitions in DNA.

We have analyzed the effect of base composition at the center of symmetry of inverted repeated DNA sequences on cruciform transitions in supercoiled DNA. For this we have constructed two series of palindromic DNA sequences: one set with differing center and one set with differing center and arm sequences. The F series consists of two 96-base pair perfect inverted repeats which are identical except for the central 10 base pairs which consist of pure AT or GC base pairs. The S series was constructed such that the overall base composition of the inverted repeats was identical but in which the positioning of blocks of AT- and GC-rich sequences varied. The rate of cruciform formation for the inverted repeats in plasmid pUC8 was dramatically influenced by the 8-10 base pairs at the center of the inverted repeat. Inverted repeats with 8-10 AT base pairs in the center were kinetically much more active in cruciform formation than inverted repeats with 8-10 GC base pairs in the center. These experiments show a dominant influence of the center sequences of inverted repeats on the rate of cruciform formation.

Base Sequence↗