Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During a six-month period, 600 gynecological samples were collected from 585 women with typical herpes lesions, women with non-herpes symptoms (ie, vaginitis, moniliasis, trichomoniasis, etc), and normal women seen at the student health center gynecological clinic and processed for herpes simplex virus (HSV) isolation. From these specimens, 29 samples from 25 of the 585 women (4.3%) were positive for HSV. When these isolates were typed using plaque diameter in chick cells, heat stability of viral thymidine kinase (T.K.), and restriction endonuclease patterns it was found that 18 samples (15 patients or 60%) were HSV-2 and 11 samples (10 patients or 40%) were HSV-1. Inapparent HSV infections constituted 20.0% of the virologically confirmed samples (5 of 25 patients) and represented 0.9% of the total patients studied (5 of 585). The inapparent infections were about equally divided between the two HSV types (2 were HSV-2 and 3 were HSV-1), and 4 of 5 occurred in the presence of clinically diagnosed monilia.
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PMID:Inapparent genital herpes simplex virus infection in college women. 629 59

Restriction endonuclease analyses of herpes simplex virus (HSV-1) DNAs revealed variability in the electrophoretic migration of specific Bam HI and Kpn I fragments. The variable regions of the genome map at the ends and near the ends of both L and S components, near the L-S junction region and in middle of the S component. The variability of the fragments was demonstrated by comparing the electrophoretic mobility patterns of DNAs from plaque-purified stocks originally derived from a common parental plaque-purified virus stock. Our analyses suggest that DNA sequences contained in the variable fragments can undergo accretion or deletion. So far the variability of the HSV-DNA molecules has been explained in terms of number of copies of terminally reiterated sequences (Wagner et al., 1978, Locker et al., 1979, Lonsdale et al., 1980, Davison et al., 1981). Our results may be explained by unequal crossing over, slippage, because of the presence of reiterated sequences, or by the presence of transposable elements.
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PMID:The heterogenous regions in herpes simplex virus 1 DNA. 631 98

A lymphocytic leukemia induced by the oncogenic DNA simian virus 40 (SV40) in an inbred LSH/SsLak Syrian golden hamster was evoked to produce infectious SV40 by fusion of the leukemia cells with grivet monkey kidney (GMK) cells and by exposure of the leukemia cells to the chemical inducers mitomycin C and cycloheximide. Plaque-purified viable substrains of the rescued SV40 when studied by restriction endonuclease digestion of viral DNA were found to contain small deletions within the Hind III restriction fragment C. These deletions lay near the viral origin of DNA replication. Ten plaque-purified substrains of the rescued virus identified by immunofluorescence as being SV40 were found, when compared to the wild-type SV40, to replicate slowly and to form small plaques. Although these substrains transformed NIH/3T3 cells as efficiently as the wild-type SV40 in tissue culture, they were generally less oncogenic in vivo--7 of the 10 failed to induce tumors. The 3 oncogenic SV40-rescued substrains were not found to exhibit "lymphocytotropism," i.e., the capacity to infect and neoplastically transform preferentially hamster lymphocytes. Thus the hamster lymphocytic leukemia originally induced by the wild-type SV40 was most likely a chance-stochastic event rather than the result of tropism-determinism mediated by the virus, as is usually the case with leukemogenic RNA viruses.
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PMID:Biologic properties of viable deletion mutants of simian virus 40 (SV40) rescued from the cells of an SV40-induced hamster lymphocytic leukemia. 631 36

The deoxyribonucleic acid (DNA) of pseudorabies virus (PRV) was examined by restriction endonuclease analysis before and after various treatments: namely 1. plaque purification of stock virus, 2. serial passage of virus in cell culture at high (H) and low (L) multiplicity of infection (MOI), and 3. serial passage of virus in swine. The objective of the study was to determine if such treatments would either select or induce virus populations with a different predominant number or location of enzyme cleavage sites. Heterogeneity of the DNA of stock virus was revealed by differences among restriction patterns of 10 plaque-purified populations. All of these populations were then relatively stable through an additional 9 plaque purifications and passages in cell culture. Without plaque purification, heterogeneity was not evident. The predominant restriction pattern of stock virus appeared unaltered by 10 serial passages in cell culture at either HMOI or LMOI, except for the appearance in the HMOI series of several minor bands. Conversely, 10 serial passages of stock virus in swine resulted in either selection or induced changes or both. Most differences were slightly altered migration rates of relatively small (less than or equal to 5 Kbp) fragments. However, after 10 passages in swine, there were also changes in the migration rates of 2 large fragments (greater than 10 Kbp) of the viral genome.
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PMID:Restriction endonuclease analysis of the pseudorabies (Aujeszky's disease) virus before and after serial passage in vivo and in vitro. 631 95

The structures of a series of plaque-forming metJB transducing phage were studied by restriction endonuclease mapping and enzyme activity assay. One of these phage, lambda pmet100, was inactivated by heat shock in the presence of EDTA, and deletion mutants were selected from the survivors. Two of these mutants, lambda pmet100 delta 1 and lambda pmet100 delta 2, were used to confirm the gene order metJ metB when moving clockwise on the linkage map of Escherichia coli K-12. Additional results indicate that the metB gene can be expressed independently of any other component of the met regulon and that the metJ gene also forms a separate transcription unit.
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PMID:Physical organization of the metJB component of the Escherichia coli K-12 metJBLF gene cluster. 631 57

Spodoptera frugiperda MNPV was plaque-purified, and the viral DNA from the plaque-purified isolates was analyzed with restriction endonuclease enzymes. Seven distinct variants were identified when the DNA of the isolates were analyzed by EcoRI and HindIII. The DNAs of the SfMNPV predominant type (prototype) and the variants were mapped with BamHI, BglII, BstEII, EcoRI, HindIII, KpnI, and PstI by multiple enzyme digestion and blot hybridization. The cleavage sites generated by the seven restriction enzymes were ordered, and the sites were assigned map coordinates using a least-squares procedure. Since Autographa californica MNPV-E2 EcoRI fragment I, which contains the polyhedrin gene, hybridized with SfMNPV EcoRI fragment P, the physical map of SfMNPV was oriented with EcoRI P on the left, with site 1 being the EcoRI site between fragments F and P. The calculated genome size was 121.76 kilobase pairs or 80.36 X 10(6) Da. The DNA from each variant was compared to the DNA of the prototype for insertions, deletions, and new restriction sites. Physical maps were generated for each of the variants. The differences between the variant and the prototype were confined to four regions in the SfMNPV genome representing less than 16% of the prototype genome.
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PMID:Physical maps of SfMNPV baculovirus DNA and its genomic variants. 633 Sep 92

Bacteriophages of methanotrophic bacteria were isolated from 67 fish. Only two phages isolated from two fish species specifically lysed Methylocystis sp. and Flavobacterium gasotypicum. The phages lysing these species were designated 63-F and CMF-1-F, respectively. The isolated phages differed greatly in the fine structure of the virion, plaque morphology, spectrum of lytic action, serological properties, and UV sensitivity. At the same time, they had identical one-step growth characteristics: their latent period equalled 5 h, lysis time was 3 to 4 h, and burst size was about 240 virions. The phages had guanine- and cytosine-rich double-stranded DNAs consisting of common nitrogen bases. The molecular masses of the DNAs as determined by the sums of restriction endonuclease cleavage fragments were 28 X 10(6) daltons for phage 63-F and 31 X 10(6) daltons for phage CMF-1-F.
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PMID:Bacteriophages of methanotrophs isolated from fish. 641 69

A specialized transducing phage lambda b221poriCasnA has been isolated carrying oriC the origin of chromosomal replication of Escherichia coli. All phage genes required for lytic growth are retained, thus the phage is capable of lytic growth. The presence of the oriC locus confers upon infecting phage DNA the ability to replicate as a plasmid using only host DNA replication functions. The presence of both oriC and ansA markers has allowed the development of a plaque assay for origin function which can be used to identify mutants at these loci. Comparison of restriction endonuclease cleavage sites present on lambda b221proiCasnA DNA to those on its parent, lambda b221 rex::Tn10 suggests the steps involved in the formation of the transducing phage.
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PMID:Isolation and characterization of lambda b221poriCasnA, a plaque-forming specialized transducing phage carrying the origin of replication of the Escherichia coli chromosome. 644 49

Chromosomal DNA of Bacillus subtilis 168 (trpC2) prepared from defective phage P BSX was digested by restriction endonuclease Eco RI and ligated in vitro with DNA fragments of page phi 105C digested by the same endonuclease. The ligated DNA was used to transform a competent culture of B. subtilis (trpC2 lys3 metB10) which was lysogenic for phi 105, and transformants of the auxotroph markers were selected. The bacterial DNA ligated to the phage DNA fragments could be integrated into the prophage genome by transformation. The transformants in toto were treated with mitomycin C and the lysate was used to transduce B. subtilis (trpC2 lys3 metB10). Among metB+ transductants, one clone appeared to be a double lysogen carrying both plaque forming and metB+ transducing phage genomes. The latter defective phage was designated phi 105dmetB. Physical mapping of these phages was carried out by agarose gel electrophoresis of the restriction endonuclease digests and also by electron microscopic analysis of heteroduplex DNA. These results indicate that two adjacent fragments Eco RI-G and E of phi 105 DNA had been substituted with a foreign fragment Eco RI-M in phi 105dmetB DNA. Transformation experiments showed that the metB+ gene resided on the fragment Eco RI-M. This fragment was found to have a BamHI-sensitive site. The transforming activity for the metB marker, however, was not affected by the treatmment with BamHI.
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PMID:A specialized transducing phage constructed from Bacillus subtilis phage phi 105. 676 51

Two genomic variants of vaccinia virus isolated from serially propagated stocks were used to demonstrate marker rescue. The smaller (S variant) virus contains a 6.3 megadalton (MDal) deletion of unique DNA sequences present in the 123-MDal larger (L variant) virus. The deletion was mapped at 6.85 MDal from the left terminus of the genome, just outside of the inverted terminal repetition. Rescue of the unique deleted DNA sequences by infectious S variant virus was obtained in CV-1 cells by using the calcium orthophosphate precipitation technique of intact or restriction endonuclease-treated L-variant DNA. Restriction fragments that overlapped the deletion allowed marker rescue, but restriction of the L-variant DNA within the unique deleted sequences gave negative results. Restriction endonuclease analysis of the DNA obtained from twice-plaque-purified recombinant virus derived from the rescue of overlap donor fragments gave a restriction pattern identical to that of L-variant virus, indicating that the donor DNA was inserted into the rescuing virus by double recombination. No amplification of the unique sequences was observed from intact L-variant DNA in the absence of infectious S-variant virus, suggesting that deproteinized vaccinia DNA is noninfectious and that the donor DNA was neither integrated into the host DNA nor present as an episomal structure. By using 1 microgram of intact L-variant DNA per CV-1 monolayer in a 6-cm Petri dish, approximately 1--5% of the plaques contained the L-variant genotype, and the dose--response curve was essentially linear from 0.1 to 2 microgram of DNA.
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PMID:Molecular genetics of vaccinia virus: demonstration of marker rescue. 695 Nov 97


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