Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

NIH 3T3 cells were transfected with restriction endonuclease and cloned human cytomegalovirus DNA fragments to identify the transforming region(s). Cleavage of human cytomegalovirus strain AD169 DNA with XbaI and HindIII left a transforming region intact whereas EcoRI inactivated this function. Transfection of cells with cosmids containing human cytomegalovirus DNA spanning the entire genome resulted in transformation by one cosmid, pCM1058, with the AD169 HindIII DNA fragments E, R, T, and a'. Cells were selected for their growth in 1.2% methylcellulose. The clones isolated had a significant replating efficiency and were oncogenic in BALB/c nu/nu mice. Transfection of cosmids and plasmids containing subsets of the viral sequences in pCM1058 identified a common region possessed by all of the transforming recombinant molecules. This region was in the HindIII E fragment with the left boundary defined by the EcoRI d-R junction and the right boundary defined by the HindIII E-T junction. Further mapping and transfection experiments determined that the transforming region was contained without a 2.9-kilobase fragment between map units 0.123 and 0.14 on the prototype molecule of the AD169 strain.
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PMID:Transformation of NIH 3T3 cells with cloned fragments of human cytomegalovirus strain AD169. 628 19

The cloned HindIII fragments of human cytomegalovirus (HCMV) strain AD169 DNA were mapped with respect to the BamHI, EcoRI and PstI restriction endonuclease cleavage sites. Composite restriction endonuclease cleavage maps for the entire virus genome were constructed using the previously established linkages between the HindIII fragments.
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PMID:Human cytomegalovirus DNA: BamHI, EcoRI and PstI restriction endonuclease cleavage maps. 629 Mar 39

The magnitude of the genetic relatedness of the two antigenic subtypes of equine herpesvirus 1 (EHV-1) was determined by DNA-DNA reassociation kinetics. Denatured, labeled viral DNA from one EHV-1 subtype was allowed to reassociate in the presence or absence of the unlabeled heterologous viral DNA. The initial rate of reassociation of either labeled viral DNA was increased by the presence of the heterologous viral DNA to an extent indicating 10 to 20% homology between the two EHV-1 genomes. Similar estimates of the amount of homology between the genomes of the two EHV-1 subtypes were obtained by determining the maximum fraction of labeled viral DNA that could be made resistant to S1 nuclease by hybridization with a large molar excess of the unlabeled, heterologous viral DNA. Analysis of the thermal stability of the subtype 1-subtype 2 heteroduplex DNA indicated approximately 30% base pair mismatching within the hybrid DNA molecules. Cross-hybridization of 32P-labeled virion DNA to nitrocellulose blots of restriction endonuclease cleavage fragments of each EHV-1 subtype DNA indicated that the observed homology between the two viruses was nonuniformly distributed with the viral genome. No homology could be detected between the DNA of either EHV-1 subtype and that of a strain of equine cytomegalovirus (EHV-2). The data suggest that the two biotypes of EHV-1 have arisen by divergent evolution from a common progenitor herpesvirus.
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PMID:Assessment of the base sequence homology between the two subtypes of equine herpesvirus 1. 629 88

The physical maps of the DNAs of two cytomegalovirus isolates, AD169 and SG, were compared by cross-blot hybridization and by hybridization of nitrocellulose-bound SG fragments with cloned 32P-labelled AD 169 fragments. From this comparison it can be concluded that both physical maps are co-linear to a large extent. Most variability existed at the termini of the long and short component (at the repeats). Other differences were the presence or absence of restriction endonuclease cleavage sites.
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PMID:Comparison of the physical maps of the DNAs of two cytomegalovirus strains. 629 5

Mouse and human DNA used as in vitro-labeled "high-complexity" probes revealed hybridization between specific herpesvirus DNA fragments on Southern transfers and repetitive sequences present at 10(3) to 10(5) copies per mammalian cell genome. Several different sites of major cell-virus sequence homology have been detected in both the herpes simplex virus type 1 and type 2 genomes, and these are located predominantly within the L and S inverted repeat regions and near the center of the L unique region. The hybrids persisted even in relatively stringent conditions, and appear to correlate closely with some of the previously recognized regions of size heterogeneity in the viral genome. Cloned viral DNA fragments from each site hybridized to different sets of discrete bands and dispersed elements within restriction-endonuclease-digested genomic DNA from a variety of vertebrate species. Localized cell-virus homology was also detected in both the human Epstein-Barr virus and cytomegalovirus genomes.
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PMID:Homology between mammalian cell DNA sequences and human herpesvirus genomes detected by a hybridization procedure with high-complexity probe. 629 53

Premature identical twins are described who according to molecular fingerprinting of their viral isolates, demonstrate a nonmaternal nursery source for their acquired cytomegalovirus (CMV) infections. The babies were born via cesarean section at 29 weeks gestation. Weekly urine screening of the infants indicated that at birth both were CMV-negative. Twin B developed CMV at 6 weeks of age, while Twin A developed his infection when he was 9 weeks old. Three months following delivery cervical and urine cultures of the infants' mother were negative and she had no detectable CMV antibody. At 6 months postpartum (2 months following both infants' discharge home) a repeat urine culture of their mother was positive for CMV, and here CMV-CF titer had risen to 1:128. DNA fingerprinting by restriction endonuclease digestion analyses of the viruses isolated from the two infants indicate that they were infected with different strains of CMV. In addition the DNA fingerprinting pattern of the mother's isolate is identical to that of Twin A. These cases give further evidence that hospitalized infants may acquire CMV from hospital sources and document by molecular fingerprinting for the first time to our knowledge that these babies may transmit the virus to CMV-seronegative individuals. This study also demonstrates how restriction endonuclease digestion analyses can be used as a powerful tool to study the epidemiology of CMV infections.
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PMID:Molecular epidemiology of cytomegalovirus infections in premature twin infants and their mother. 629 54

We have cloned EcoRI and HindIII fragments of the Smith strain of murine cytomegalovirus (MCMV) in the plasmid vector pACYC184. These cloned fragments were used to establish a restriction endonuclease map of the genome with respect to the EcoRI and HindIII sites. The map was constructed on the basis of data derived from cross-hybridizations of EcoRI and HindIII cloned fragments, double-digestions of the cloned fragments with EcoRI and HindIII, and hybridization of cloned HindIII fragments to Southern blots of MCMV DNA cleaved with EcoRI. From our mapping data, we have determined that the length of the MCMV genome is approximately 240 kbp. The genome does not appear to undergo inversions and lacks detectable repeated sequences. One HindIII cloned fragment was obtained which contained both HindIII termini. The existence of this fragment may be related to the mode of replication of the MCMV genome.
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PMID:Molecular cloning and restriction endonuclease mapping of the murine cytomegalovirus genome (Smith Strain). 631 Aug 88

Murine cytomegalovirus (MCMV) Smith strain DNA is cleaved by restriction endonuclease HindIII into 16 fragments, ranging in size from 0.64 to 22.25 megadaltons. Of the 16 HindIII fragments, 15 were cloned in plasmid pACYC177 in Escherichia coli HB101 (recA). The recombinant plasmid clones were characterized by cleavage with the enzymes XbaI and EcoRI. In addition, fragments generated by double digestion of cloned fragments with HindIII and XbaI were inserted into the plasmid vector pACYC184. The results obtained after hybridization of 32P-labeled cloned fragments to Southern blots of MCMV DNA cleaved with HindIII, XbaI, EcoRI, BamHI, ApaI, ClaI, EcoRV, or KpnI allowed us to construct complete physical maps of the viral DNA for the restriction endonucleases HindIII, XbaI, and EcoRI. On the basis of the cloning and mapping experiments, it was calculated that the MCMV genome spans about 235 kilobase pairs, corresponding to a molecular weight of 155,000,000. All fragments were found to be present in equimolar concentrations, and no cross-hybridization between any of the fragments was seen. We conclude that the MCMV DNA molecule consists of a long unique sequence without large terminal or internal repeat regions. Thus, the structural organization of the MCMV genome is fundamentally different from that of the human cytomegalovirus or herpes simplex virus genome.
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PMID:Molecular cloning and physical mapping of murine cytomegalovirus DNA. 631 75

The genome of guinea pig cytomegalovirus (GPCMV) was analyzed and compared with that of human cytomegalovirus (HCMV). GPCMV and HCMV DNAs were isolated from virions and further purified by CsCl centrifugation. Purified GPCMV DNA sedimented as a single peak in a neutral sucrose gradient and was infectious when transfected into guinea pig embryo fibroblast cells. The cytopathology was characteristic of that seen after infection with GPCMV. Virus DNA purified from virions isolated from infected GPEF or 104C1 cells had a CsCl buoyant density of 1.713 g/cm3, which corresponds to a guanine plus cytosine content of 54.1%. The CsCl buoyant density of GPCMV DNA was slightly less than that of HCMV DNA (1.716 g/cm3), but sufficiently different so that the two virus DNA peaks did not coincide. GPCMV DNA cosedimented with T4 DNA in a neutral sucrose gradient. Restriction endonuclease cleavage of GPCMV or HCMV DNAs with HindIII, XbaI, or EcoRI yielded fragments easily separable by agarose gel electrophoresis and ranging from 1.0 X 10(6) to 25.8 X 10(6) daltons. The number, size, and molarity of GPCMV DNA fragments generated by restriction enzymes were determined. Hybridization of restriction endonuclease-cleaved GPCMV DNA with radioactively labeled HCMV DNA and, conversely, hybridization of restriction endonuclease-cleaved HCMV DNA with radioactively labeled GPCMV DNA indicated sequence homology between the two virus DNAs.
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PMID:Characterization of guinea pig cytomegalovirus DNA. 631 42

The nucleocapsids (N-capsids) isolated from the nuclei of rat cytomegalovirus (RCMV)-infected rat embryo fibroblasts (REF) are composed of three major proteins: 142 X 10(3) (142K), 40K and 32K mol. wt. Nucleocapsids isolated from the cytoplasmic fraction (C-capsids) are composed of proteins found in N-capsids and five major and seven minor new protein species. Most of the proteins present in C-capsids are found in the extracellular enveloped virions, although the ratios vary. Proteins that are abundantly present, particularly in virions (mol. wt. 125K, 116K, 87K, 79K, 71K, 68K, 62K, 50K, 43K and 28K), are probably the major constituents of the viral envelope. The DNA recovered from extracellular virions was purified to homogeneity and by equilibrium centrifugation in CsCl one density class of 1.716 (+/- 0.001) g/ml was found. Contour length measurements showed one size class of a linear double-stranded DNA corresponding to an average mol. wt. of 144(+/-9) X 10(6) which is in good agreement with data obtained by restriction endonuclease analysis (REA), which yielded mol. wt. values of 132(+/-9) X 10(6) (HindIII), 138(+/-2) X 10(6) (EcoRI) and 137 X 10(6) (BglII). The REA patterns also revealed the presence of 0.25 M and 0.5 M fragments, which might indicate, in analogy with other cytomegalo- and herpesviruses, the existence of four different configurations of the RCMV genome. The infectivity of RCMV DNA was determined in subconfluent REF monolayers. A cytopathic effect characteristic of RCMV was observed 6 days post-transfection and up to 60 plaques/microgram DNA were obtained. Using DNA-DNA filter hybridization the degree of homology between the genomes of RCMV and murine or human CMV was examined. Under stringent conditions (50% formamide) values of 12(+/-2)% and 3(+/-1)% were found whereas under non-stringent conditions (20% formamide) values of 21(+/-2)% and 6 (+/-1)% were obtained, respectively.
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PMID:Rat cytomegalovirus: studies on the viral genome and the proteins of virions and nucleocapsids. 632 18


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