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)

Based on the results of a systematic study of factors affecting plasmid yield and purity, a procedure suitable for the rapid screening for and isolation of covalently closed circular DNA from Streptomyces lividans and Escherichia coli was developed. The method consists of lysis of lysozyme-treated bacteria combined with alkaline denaturation of DNA at high temperature. Renaturation of CCC DNA and precipitation of single-stranded DNA together with protein is achieved by the addition of a minimal amount of phenol/chloroform. The screening procedure uses only a single tube and the samples can be analyzed by agarose gel electrophoresis about 30 min after lysis. Removal of phenol and further purification of the plasmid preparation is achieved by consecutive precipitations with isopropanol and spermine, followed by extraction with ethanol, producing samples suitable for restriction endonuclease digestion, ligation, and transformation of S. lividans protoplasts or competent E. coli cells in about 2 h. All steps of the procedure are explained in detail with information about the effects of changing parameters. This should help the experimenter to obtain reproducible results and may be useful if the method has to be adapted to new strains or plasmids.
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PMID:Factors affecting the isolation of CCC DNA from Streptomyces lividans and Escherichia coli. 638 33

Procedures are described for the detection and isolation of plasmids of various sizes (2.6 to 350 megadaltons) that are harbored in species of Agrobacterium, Rhizobium, Escherichia, Salmonella, Erwinia, Pseudomonas, and Xanthomonas. The method utilized the molecular characteristics of covalently closed circular deoxyribonucleic acid (DNA) that is released from cells under conditions that denature chromosomal DNA by using alkaline sodium dodecyl sulfate (pH 12.6) at elevated temperatures. Proteins and cell debris were removed by extraction with phenol-chloroform. Under these conditions chromosomal DNA concentrations were reduced or eliminated. The clarified extract was used directly for electrophoretic analysis. These procedures also permitted the selective isolation of plasmid DNA that can be used directly in nick translation, restriction endonuclease analysis, transformation, and DNA cloning experiments.
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PMID:Rapid procedure for detection and isolation of large and small plasmids. 700 83

The transfer of tetracycline resistance among strains of Clostridium difficile is described. Transfer occurred by a conjugation-like event that was insensitive to deoxyribonuclease, could not be mediated by donor culture filtrates or chloroform-treated donor cultures, and required cell-to-cell contact. Tetracycline-resistant progeny recovered from matings displayed a resistance phenotype identical to that of the donor in level of resistance, constitutive expression, and transmissibility. Although the original tetracycline-resistant donor contained 5 x 10(6)- and 22 x 10(6)-dalton plasmids, standard physical analyses of antibiotic-resistant transconjugants revealed no plasmid deoxyribonucleic acid molecules in common with the donor strain. Furthermore, tetracycline-susceptible derivatives of the original donor always possessed a plasmid complement identical to that of the resistant parental strain as determined by restriction endonuclease digestion analysis. The results indicate that the tetracycline resistance determinant(s) was not encoded by readily detectable plasmid deoxyribonucleic acid and may be chromosomally located.
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PMID:Transferable tetracycline resistance in Clostridium difficile. 727 Dec 79

This study evaluated the Promega Magic Minipreps (MM) (Promega Corporation, Madison, WI) DNA purification system for use in plasmid analysis of common nosocomial bacterial pathogens. The MM system is a kit that includes lysis solutions and buffers and incorporates a minicolumn of DNA binding resin for recovery of plasmid DNA. The MM system was used according to the manufacturer's directions to recover plasmids for agarose gel electrophoresis from clinical isolates of Acinetobacter calcoaceticus, Enterobacter cloacae, and Klebsiella pneumoniae. For Salmonella enteritidis and Staphylococcus aureus, lysozyme and lysostaphin, respectively, were used for pretreatment. Plasmid DNA from ten isolates could be recovered in approximately one hour with very little manipulation and no phenol/chloroform extractions and was suitable for restriction endonuclease digestion. Compared with a standard miniprep protocol, the MM system was much easier to perform and resulted in significant cost savings due to a 50% reduction in technologist time. The authors conclude that the MM system is a convenient and cost-effective method for clinical microbiology laboratories for recovering plasmid DNA from nosocomial bacterial pathogens.
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PMID:Evaluation of a commercial DNA purification system for plasmid analysis of nosocomial bacterial pathogens. 837 41

The first isolation of Lactobacillus plantarum bacteriophages from ruminal fluid is reported. Three bacteriophages were characterized on the basis of plaque morphology, host ranges, stability, electron microscopic morphology and DNA restriction endonuclease digestion patterns. They formed clear plaques and are placed in group A of Bradley's scheme and have identical host ranges. Bacteriophages were stable to urea and chloroform. They were relatively thermostable but partially inactivated by rumen fluid and by acetate. DNA restriction analysis showed that phage L20 had different numbers of cleavage sites in comparison with the next two phages.
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PMID:Isolation and partial characterization of three rumen Lactobacillus plantarum bacteriophages. 851 May 72

The lack of simple and efficient methods for extraction of DNA from Nocardia spp. has hampered molecular manipulation of the DNA for diagnostic purposes. In the present study, a method for the rapid extraction of undegraded genomic nocardial DNA was established. Briefly, 14 pathogenic Nocardia strains were grown at 37 degrees C for 3 to 5 days in Sauton broth containing 0.05% Tween 80. Subsequently, the cultures were treated for 48 h with 1.2 mg of cycloserine per ml (final concentration). Cells were then harvested by centrifugation and treated with a lysis solution containing 3 mg of lysozyme per ml. This was followed by the addition of proteinase K and sodium dodecyl sulfate to final concentrations of 0.2 mg/ml and 0.5%, respectively, and incubation for 1 h at 50 degrees C. DNA was precipitated with isopropanol after phenol-chloroform-isoamyl alcohol extractions and RNase treated before being quantitated and analyzed by agarose gel electrophoresis. The average undegraded DNA yields obtained were 101 micrograms for Nocardia brasiliensis and 121 micrograms for N. asteroides. This DNA was suitable for restriction endonuclease digestion and PCR amplification, which are methods being applied to the characterization and diagnosis of slowly growing organisms such as Nocardia spp.
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PMID:A rapid and gentle method for isolation of genomic DNA from pathogenic Nocardia spp. 887 44

A new method for isolation of prawn baculovirus and subsequent extraction of viral DNA was developed. No density gradient centrifugation, ultracentrifugation or phenol-chloroform extraction steps were involved. Phenylmethylsulfonyl fluoride (PMSF) was used to prevent proteinase degradation, DNase and RNase were used to degrade prawn DNA and RNA respectively. The nucleocapsid was a bacilliform virion, about 58 62 nm in width and 300-350 nm in length as observed by transmission electron microscopy. Intact viral DNA was obtained by lysing nucleocapsids with guanidine hydrochloride and degrading protein with proteinase K. As the viral DNA was digested with restriction endonuclease and separated by electrophoresis, restriction fragments were clearly shown on the agarose gel. The size of the DNA was estimated approximately to be 290 kb. The virus which appeared to be a prawn baculovirus was named prawn white spot baculovirus (PWSBV) due to the white spots which appeared on the inside surface of the crust of infected prawns.
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PMID:A simple and efficient method for purification of prawn baculovirus DNA. 927 11

Properties of natural hybrid transposable phages (TP) of Pseudomonas aeruginosa, including phage PL24 and lysogens for this phage, were studied. PL24 possesses the properties of TP from two previously described groups, B3 and D3112. Its genome, unlike the genome of D3112, contains many sites susceptible to the SalGI restriction endonuclease and possesses no more than 100 nucleotides of bacterial origin located at the left genome end. However, unlike B3, phage PL24 failed to induce auxotrophic mutants upon integration in the bacterial genome. This phage differed from both B3 and D3112 in sensitivity to chloroform treatment. A more detailed examination of a group containing 25 randomly isolated lysogens for phage PL24 revealed previously unknown processes occurring at early stages of bacterial lysogenization. There are at least two different modes of cell lysogenization with phage PL24. In the first case, the emerging lysogens contained a single prophage genome located (in each lysogen) at individual sites. In the second case, polylysogenic bacteria appeared, and, after primary integration of a phage genome, replicative transposition occurred at new sites (often accompanied by the appearance of prophage clusters at these sites). The choice of the mode of lysogenization can be determined both by differences in the physiological state of bacteria and by specific features of phage PL24, which possibly affect the time of repressor accumulation to the concentration sufficient for blocking phage growth or the stability of the lysogenic state.
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PMID:[Properties of natural interspecific hybrids of transposable phages of Pseudomonas aeruginosa: specific characteristics of phage PL24 transposition]. 1109 44

A rapid method of ultracentrifugation pelleting of avian adenovirus (AAV) from small volume of chloroform treated infected cell culture fluid or allantoic fluid was adapted for isolation of adenoviral DNA. The viral DNA extracted from semipurified viruses was found to be intact on agarose gel and pure enough (A260/280 = 1.85-1.92) for restriction enzyme analysis. Restriction endonuclease analysis of Indian strain of AAV serotype 1, AAV serotype 4 (group I AAVs) and egg drop syndrome-76 (EDS-76) virus genomes (group III AAV) with Hind III enzyme differentiated these viruses. The AAV serotype 1 and serotype 4 strain exhibited identical Hind III profile to European viral strains belonging to same serotypes however, the EDS-76 virus gave similar but not identical profile. The calculated genomic lengths for AAV serotype 1 and EDS-76 virus were approximately found to be 33.9 and 44.4 Kb, respectively.
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PMID:Purification and differentiation of three avian adenoviruses by restriction endonuclease analysis. 1121 38

This report describes a method for the isolation of nucleic acid from a suspension of matured virus. Nucleic acid (DNA) was isolated from a prototype strain of adenovirus type 7 and a clinical isolate of adenovirus type 7. Instead of the usual method of ultracentifugation, a filtration method was applied to concentrate the virus rapidly and nucleic acid was then isolated by a standard phenol/chloroform/isoamyl-alcohol extraction procedure. The DNA was found to be sufficiently purified to generate a reproducible restriction endonuclease digestion pattern. The clinical isolate of adenovirus type 7 revealed loss of restriction site for the endonuclease HindIII when compared with the prototype strain.
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PMID:A modified rapid method of nucleic acid isolation from suspension of matured virus: applied in restriction analysis of DNA from an adenovirus prototype strain and a patient isolate. 1139 95


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