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)

The restriction fragment patterns of two mutants forms of the temperate Bacillus subtilis bacteriophage SP beta have been examined. The DNA of a heat-inducible mutant, SP beta c2, which has a molecular size of 128 kilobases (kb), yields the same restriction pattern as the wild type SP beta c+ DNA. The DNA of a clear-plaque mutant, SP beta c1, has a molecular size of 117 kb, and is deleted for an 11 kb region of phage DNA. Neither SP beta c1 nor SP beta c2 DNA is cleaved by the endonuclease HaeIII.
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PMID:Bacillus subtilis bacteriophages SP beta c1 is a deletion mutant of SP beta. 627 67

The purification of orf virus directly from scab material from clinical cases of orf in sheep and restriction endonuclease analysis of the viral DNA is described. Between 7 x 10(9) and 1.6 x 10(11) virus particles, and 0.7 to 22.8 micrograms of viral DNA could be recovered from 1g of scab material. Considerable heterogeneity was observed between different field isolates when restriction endonuclease digests of orf DNA were compared by gel electrophoresis. It was also shown, for two isolates, that these fragment patterns did not change after plaque purification and passage in cell culture. It is suggested that restriction endonuclease analysis of viral DNA offers a convenient method of identification of isolates of orf virus. The molecular weight of orf DNA was determined and found to be 88.8 x 10(6).
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PMID:The genome of orf virus: restriction endonuclease analysis of viral DNA isolated from lesions of orf in sheep. 627 55

The ganglia of rabbits infected with a relatively benign strain of herpesvirus (E-43) and challenged with either of two virulent neurotrophic strains (MP or McKrae) were found to be colonized only by the initial benign infecting strain. Primary infection with the E-43 strain resulted in milder disease when the animals were infected with MP or McKrae strains and also prevented colonization of the ganglion by these strains. Neutralization with anti-glycoprotein C, plaque morphology, cytopathic effects, reconstruction experiments, and restriction endonuclease analysis indicated that the virus recovered from the ganglion was the initial infecting E-43 strain; no traces of the challenging MP and McKrae strains were found. The challenging McKrae strain was shed for several weeks in a few animals, but the virus isolated from the trigeminal ganglia of these animals was the primary infecting E-43 strain. These results suggest that initial infection with a relatively benign strain of herpesvirus may prevent superinfection of the ganglion (but not necessarily the end organ) by highly virulent herpes simplex virus strains and could have significant implications in the consideration of immunization against this disease in humans.
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PMID:Initial herpes simplex virus type 1 infection prevents ganglionic superinfection by other strains. 627 13

The molecular and serologic relatedness of 2 recent respiratory tract isolates of equine herpesvirus type 1, designated T1 and T2, were compared with the Army 183, Kentucky-A hamster-adapted (KyA-ha), and L-M cell-adapted (KyA-LM) strains. Electrophoresis in polyacrylamide gels revealed differences in virion structural proteins among 4 purified strains. Seven envelope glycoproteins (molecular weight of 93,000, 65,000, 62,000, 60,000, 36,000, 20,000, and 18,000) corresponding to virion proteins 13, 16, 17, 18, 23, 25, and 26a, respectively, found in both the Army 183 and KyA-ha strains had slightly different molecular weight counterparts in both the T1 and T2 isolates, which had identical structural protein profiles. virion protein 19 (58,000 daltons), a nonglycosylated protein, was present in reduced amounts in the respiratory tract isolates, whereas virion protein 8a (200,000 daltons) was absent. Virion protein 8a, an envelope glycoprotein, was only present in the KyA-ha strain. The T1 and T2 isolates were not neutralized by equine herpesvirus type 2 antiserum and revealed little cross-neutralizatio with the Army 183 and KyA-ha strains in plaque-reduction neutralization tests. Restriction endonuclease cleavage maps of viral DNA revealed a similar, but not identical, number and size of DNA fragments between T1 and T2 isolates. Likewise, DNa profiles of Army 183, KyA-ha, and KyA-LM were also similar to each other, but vastly different from the respiratory tract isolates.
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PMID:Serologic and molecular comparisons of several equine herpesvirus type 1 strains. 628 May 20

A specialized transducing phage for the srlA gene, specifying the sorbitol-specific Enzyme II of the phosphoenolpyruvate:sugar phosphotransferase system, was constructed and its DNA was analysed by restriction endonuclease digestion. Phage construction involved four steps: (1) integration of lambda into the srlA gene; (2) selection of phage carrying (a) the left and (b) the right end of the srlA gene by means independent of the function of the new DNA acquired; (3) reconstitution of the srlA gene in a dilysogen of these two phage; and (4) the excision, using the heteroimmune lambdoid phage 21, of a plaque-forming srlA+ phage from the dilysogenic chromosome. Comparison of the DNA restriction digests of the transducing phage with those of its parents and of wild-type lambda revealed fragments consisting partly of lambda and partly of Escherichia coli DNA. The junction points in the intermediate phage define a site that must lie within the reconstituted gene of the final phage. This technique should be of general application in relating genes, cloned by our method, to DNA sequences.
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PMID:A specialized transducing phage, lambda psrlA, for the sorbitol phosphotransferase of Escherichia coli K12. 628 66

A library of genomic DNA from the brine shrimp, Artemia, has been constructed with the Charon 4A phage vector, utilizing EcoRI passenger fragments. Screening this library with purified Xenopus laevis cloned rDNA genes has resulted in the identification and plaque purification of a recombinant containing a complete Artemia (18 S + 26 S) rDNA repeat unit. A physical map derived from the analysis of restriction endonuclease digests of the repeat unit, which measures 13.9 kilobase pairs, is similar to the map derived from genomic DNA. In common with several other species, the 26 S rRNA gene terminates with a HindIII recognition site.
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PMID:Molecular cloning and characterization of ribosomal RNA genes from the brine shrimp. 628 76

A rat liver DNA genomic library was prepared using the lambda phage cloning vector Charon 28. Recombinant phage were screened with a cDNA clone (pOR-7) containing sequences complementary to mRNA coding for NADPH-cytochrome P-450 oxidoreductase. This cDNA clone contains the poly(A) addition site and 60% of the mRNA sequence (Gonzalez, F. J., and Kasper, C. B. (1982) J. Biol. Chem. 257, 5962-5968). Four positive phage were identifed and plaque-purified, and their DNA was isolated and subjected to restriction endonuclease mapping. All phage DNA inserts, which ranged from 11 to 16 kilobases, contained several overlapping restriction fragments. The clone with the largest insert (lambda OR-2) was found to contain restriction fragments identical with those of rat DNA when both were subjected to Southern blotting with nick-translated pOR-7 DNA; this finding established the presence in lambda OR-2 of the 3' end (poly(A) addition site) of the oxidoreductase gene. When [32P]cDNA synthesized from enriched oxidoreductase poly(A) RNA was utilized as a probe, additional fragments were identified. The fragment most distal to the 3'-specific fragment was assumed to contain the 5' cap site and was subcloned into pBR322 for further analysis. Restriction mapping and Southern blot analysis further localized the 5' end of the gene to an AvaII fragment of 540 base pairs (bp). Hybridization of this fragment with oxidoreductase mRNA-enriched poly(A) RNA resulted in the arrest of translation of oxidoreductase; this confirmed that it contained an exon region of the oxidoreductase gene. S1 nuclease mapping and DNA sequencing identified to within +/- 1 bp the 5' cap site of the gene which corresponds to an A start. DNA sequencing of the 5'p flanking region revealed no "TATA box" in the vicinity of -25 to -30 bp of the cap site. R-loop analysis of lambda OR-2 revealed the presence of a minimum of seven introns in the 6000-bp oxidoreductase gene and eight exons with a total length of approximately 2600 bp.
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PMID:Cloning and characterization of the rat NADPH-cytochrome P-450 oxidoreductase gene. 629 77

Deletions in the cloned thymidine kinase (TK) gene of herpes simplex virus type 1 (HSV-1), strain 17 syn+, were produced by two methods. Removal of a 506 base pair fragment from between the unique SstI and Bg/II restriction endonuclease sites of pTK1 (HSV-1 BamHI p cloned in pAT153) and subsequent transformation of Escherichia coli resulted in the isolation of 50 deleted plasmids. Sequential digestion of pTK1 with Bg/II and nuclease BAL 31 followed by ligation and recleavage with Bg/II resulted in the isolation of 31 deleted plasmids. Three clones, pTK2, pTK3 and pTK4, obtained following Bg/II and SstI treatment of pTK1 were recombined with wild-type (wt) HSV-1 (17) syn+ DNA in baby hamster kidney (BHK) cells to produce TK- deletion mutants HSV-1 (17) TK 1301, HSV-1 (17) TK 1302 and HSV-1 (17) TK 1303 respectively. 5-Bromo-2'-deoxyuridine, 5-bromo-2'-deoxycytidine and 9-(2-hydroxyethoxymethyl)guanine were used to reduce the background of TK+ virus in heterogeneous recombinant stocks analysed for the presence of TK- recombinants. All recombinant clones isolated produced a small syncytial plaque morphology in BHK cells. The mutants HSV-1 (17) TK 1301 and HSV-1 (17) TK 1302 were TK-, failed to produce polypeptides of molecular weights 43000 and 19000 found in wt-infected cells and demonstrated one-step growth curves different from wt virus and the TK- mutant HSV-1 (17) dPyk-7. Superinfection studies with HSV-1 (17) TK 1301, HSV-1 (17) TK 1302, HSV-1 (MDK) and HSV-1 (17) dPyk-7 indicated that all TK- mutants except dPyK-7 produce a trans-acting gene product which can switch on the transforming HSV-1 TK gene.
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PMID:Thymidine kinase deletion mutants of herpes simplex virus type 1. 629 78

DNA from African swine fever (ASF) virus was isolated and was characterized by two restriction enzymes, SmaI and EcoRI. Although both enzymes can distinguish Vero cell-adapted ASF isolates by characteristic restriction endonuclease cleavage patterns, all ASF isolates examined exhibited a high degree of similarity, as measured by co-migration of most of the DNA fragments. The molecular weight of ASF DNA, based on size estimates of DNA fragments from cleavage patterns, ranged from 93 x 10(6) to 100 x 10(6). Virus genome heterogeneity was observed in uncloned, cell culture-adapted ASF isolates as well as in a plaque-purified virus after serial passage in Vero cells. In contrast to the rather minor differences in restriction pattern among the Vero cell-adapted isolates, a major alteration in restriction endonuclease cleavage sites was observed during adaptation of the wild-type virus to cell culture.
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PMID:African swine fever virus DNA: restriction endonuclease cleavage patterns of wild-type, Vero cell-adapted and plaque-purified virus. 629 85

A total of 122 clinical isolates of herpes simplex virus (HSV) from 107 patients were typed by using an indirect immunoperoxidase technique with commercially available type-specific rabbit antisera, recently developed mouse monoclonal antibodies to HSV types 1 and 2, and restriction endonuclease analysis of viral DNA. With the commercially available type-specific rabbit antisera, 34% of clinical HSV isolates were of indeterminate type; 63% of them were typed as HSV type 1 and 37% as HSV type 2 by using monoclonal antibody and restriction enzyme typing systems. Typing by immunofluorescence assay with the monoclonal antibodies gave identical results to those obtained by restriction enzyme analysis. Simultaneous infection with both HSV types was demonstrated by monoclonal antibody typing in five isolates from three patients. These findings were subsequently confirmed by plaque purification and restriction endonuclease analysis of viral DNA. Monoclonal antibodies were as sensitive as restriction enzyme analysis for the typing of clinical HSV isolates. Because of their simplicity, they are more amenable to use in clinical laboratories than is restriction endonuclease analysis.
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PMID:Typing of clinical herpes simplex virus isolates with mouse monoclonal antibodies to herpes simplex virus types 1 and 2: comparison with type-specific rabbit antisera and restriction endonuclease analysis of viral DNA. 629 76


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