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)

DNA from lambdagt-lambdaB bacteriophage was cleaved with EcoRI endonuclease and fragments from EcoRI-digested E. coli DNA were inserted. This DNA was used to infect E. coli, and phages containing the gene for DNA ligase were isolated by genetic selection. Two different hybrids were found with the same E. coli segment inserted in opposite orientations. Both hybrids produced similar levels of ligase as measured in crude extracts of infected cells.
Proc Natl Acad Sci U S A 1975 Sep
PMID:In vitro construction of bacteriophage lambda carrying segments of the Escherichia coli chromosome: selection of hybrids containing the gene for DNA ligase. 110 46

Cleavage of adenovirus-associated virus type 2 (AAV2) DNA linear duplex monomers with the restriction endonuclease R-EcoRI yielded three fragments, A, B, and C, having approximate mol wt of 1.6 X 10(6), 1.1 X 10(6), and 1.3 X 10(5), respectively. Radioactive labeling the 5' termini of AAV DNA before cleavage with R-EcoRI showed that A and B were terminal fragments and C was internal. Separation of the complementary strands of fragments A and B showed that A contained the 5' terminus of the minus strand and the 3' terminus of the plus strand, and conversely for fragment B. The physical map of the AAV R-EcoRI fragments can thus be unambiguously determined and is drawn with B at the left-hand and A at the right-hand end. On this map, transcription of stable AAV mRNA from the minus strand proceeds from left to right, beginning in fragment B and terminating in fragment A. The asymmetry in distribution of thymidine between the AAV DNA plus and minus strands is preferentially located in fragment A, which represents the right-hand half of the duplex molecule. These experiments enable preparative separation of all four single-strand termini of AAV DNA and provide a basis for orientation of fragment maps derived by cleavage with other restriction enzymes.
J Virol 1975 Sep
PMID:Physical map and strand polarity of specific fragments of adenovirus-associated virus DNA produced by endonuclease R-EcoRI. 115 94

Replicative form DNA of bacteriophage f1 was found to be sensitive in vitro to restriction by endonuclease R-EcoRII if the DNA was isolated from an Escherichia coli strain deficient in cytosine methylase activity. A similar observation was previously made with DNA from the closely related bacteriophage fd (S. Schlagman, S. Hattman, M. S. May, and L. Berger, submitted for publication). The two DNA fragments produced by the endo R-EcoRII digestion of f1 DNA were localized on the f1 cleavage map and their genetic content was determined. The polypeptides synthesized in a "coupled" transcription-translation system under the direction of each RII fragment were examined. The results of such experiments allow the ordering of genes V and VII and indicate the location of a RNA promotor for gene VIII.
J Virol 1975 Sep
PMID:Endonuclease R-EcoRII restriction of bacteriophage f1 DNA in vitro: ordering of genes V and VII, location of an RNA promotor for gene VIII. 115 96

DNA was extracted from rat liver of non-irradiated animals, and was irradiated in vitro, and from animals which received whole body doses of X-radiation. Sedimentation on neutral and alkaline sucrose gradients as well as measurements of 32P release after sequential treatment with endonuclease and alkaline phosphatase and determination of triphosphate incorporation after the sequential treatment with endonuclease, alkaline phosphatase and DNA polymerase indicated that DNA irradiated in vivo and in vitro were effective substrates for the mammalian repair endonuclease. The experiments suggest that in addition to strand breaks, X-radiation causes base damage and they have provided a plausible explanation for the formation of double strand breaks in DNA irradiated in vivo.
Biochim Biophys Acta 1975 Sep 01
PMID:The effect of a mammalian repair endonuclease on x-irradiated DNA. 116 20

The sequence of the first 149 nucleotides of the major leftward RNA of bacteriophage lambda has been determined. Preliminary sequence information was also obtained for a portion of the untranscribed area immediately upstream of the point on the template when RNA synthesis normally starts. Several restriction endonuclease sites, deletion endpoints, and single base changes have been localized within the sequence. The first potential translation initiation codon which is not followed by an in-phase termination codon is a GUG located 90 nucleotides from the transcription startpoint.
Nucleic Acids Res 1975 Sep
PMID:Sequence of the promoter-operator proximal region of the major leftward RNA of bacteriophage lambda. 117 25

The culture medium of Pseudomonas BAL 31 contains endonuclease activities which are highly specific for single-stranged DNA and for the single-stranded or weakly hydrogen-bonded regions in supercoiled closed circular DNA. Exposure of nicked DNA to the culture medium results in cleavage of the strang opposite the sites of preexisting single-strand scissions. At least some of the linear duplex molecules derived by cleavage of supercoiled closed circular molecules contain short single-stranded ends. Single-strand scissions are not introduced into intact, linear duplex DNA or unsupercoiled covalently closed circular DNA. Under these same reaction conditions, 0X174 phage DNA is extensively degraded and PM2 form I DNA is quantitatively converted to PM2 form III linear duplexes. Prolonged exposure of this linear duplex DNA to the concentrated culture medium reveals the presence of a double-strand exonuclease activity that progressively reduces the average length of the linear duplex. These nuclease activities persist at ionic strengths up to 4 M and are not eliminated in the presence of 5% sodium dodecyl sulfate. Calcium and magnesium ion are both required for optimal activity. Although the absence of magnesium ion reduces the activities, the absence of calcium ion irreversibly eliminates all the activities.
Nucleic Acids Res 1975 Sep
PMID:Extracellular nucleases of Pseudomonas BAL 31. I. Characterization of single strand-specific deoxyriboendonuclease and double-strand deoxyriboexonuclease activities. 117 26

A quantitative study has been made on the action of rat nuclear Ca-Mg endonuclease on rat liver nuclei. In a standard 30 minute digest 0.5-1.5% of the DNA was rendered acid soluble, 1.5-4% of the chromatin was rendered buffer soluble, 50-60% of the potential cleavage sites were actually cleaved, and these cleavages were distributed evenly throughout the bulk of the genome. During these standard digests there was no significant loss of histones either in aggregate or relative to each other. Trypsin digestion of the nuclei to a trypsin resistant core did not lower the specificity of the Ca-Mg endonuclease cleavages or expose other sites to its action. Evidence is presented that indicates Ca-Mg endonuclease and micrococcal nuclease attack the same sites rather than different sites with the same spacing.
Nucleic Acids Res 1975 Sep
PMID:The reaction of the Ca-Mg endonuclease with the A-sites of rat nucleoprotein. 117 28

The frequency of introduction and spread of specific Clostridium difficile strains among hospitalized patients were assessed by serial cultures of patients admitted to a medical-surgical ward with endemic C. difficile-associated diarrhea. Stool cultures were obtained from 634 (94%) of 678 consecutive admissions to the ward (ward admissions), and all C. difficile isolates were typed by restriction endonuclease analysis. Sixty-five ward admissions introduced C. difficile to the ward, and 54 initially culture-negative admissions acquired C. difficile on the ward. Ward admissions hospitalized within the prior 30 days in the medical center were more likely to be culture-positive for C. difficile at admission to the study ward than those not previously hospitalized at the institution (16% vs. 7%, P less than .001). Nosocomial acquisition of a C. difficile strain was preceded by a documented introduction of that strain to the ward by another asymptomatic ward admission in 16 (84%) of 19 instances, suggesting that C. difficile-colonized new admissions are a major source of nosocomial C. difficile infections.
J Infect Dis 1992 Sep
PMID:Acquisition of Clostridium difficile by hospitalized patients: evidence for colonized new admissions as a source of infection. 132 21

Apoptosis, or programmed cell death, is an endogenous cellular process whereby an external signal activates a metabolic pathway that results in cell death. This form of cell death appears to be a common feature in many biological processes where cell deletion is a mechanism for altering tissue structure and function. Historically, apoptosis has been studied using histological techniques; however, more recent interest has focused on analyzing this process at the biochemical level. A biochemical hallmark of apoptosis is a characteristic form of DNA degradation in which the genome is cleaved at internucleosomal sites, generating a 'ladder' of DNA fragments when analyzed by agarose gel electrophoresis. A number of assay systems have been developed to study this nuclease activity. For example, nuclease activity has been analyzed by measuring the release of endogenous DNA from apoptotic cells, by flow cytometric analysis of apoptotic cells and by analyzing in situ apoptotic nuclease activity in polyacrylamide gels containing DNA. Use of these assay systems has enabled investigators to study the signal transduction pathways that mediate apoptosis and to characterize the endonuclease itself. Future biochemical studies in this field will focus on isolating the genes and gene products that mediate apoptosis.
Cancer Metastasis Rev 1992 Sep
PMID:A biochemical hallmark of apoptosis: internucleosomal degradation of the genome. 132 65

Genomes of 55 Dutch porcine Serpulina (Treponema) hyodysenteriae and non-pathogenic Serpulina isolates were characterized by restriction endonuclease analysis (REA) and DNA hybridization. The Dutch porcine isolates were compared with American Type Culture Collection (ATCC) strains of S. hyodysenteriae and S. innocens and isolates of S. hyodysenteriae with known serotypes (reference strains). REA of the Dutch S. hyodysenteriae isolates resulted in two main patterns, while the non-pathogenic isolates had many distinct REA patterns, all different from the S. hyodysenteriae strains. The S. hyodysenteriae reference strains all had distinct REA patterns, different from the Dutch strains. Upon Southern hybridization with a S. hyodysenteriae DNA fragment encoding a flagellar protein, all S. hyodysenteriae strains could be divided in two groups. The non-pathogenic Serpulina strains had many distinct hybridization patterns and hybridized less intensely. Upon hybridization with a S. hyodysenteriae DNA fragment encoding a haemolysin, DNA of all S. hyodysenteriae strains reacted in the same band. DNA of non-pathogenic Dutch Serpulina strains and S. innocens did not hybridize. It was concluded that there are two main genotypes of S. hyodysenteriae in the Netherlands. This could be of importance for recombinant DNA vaccine development.
J Gen Microbiol 1992 Sep
PMID:Characterization of Dutch porcine Serpulina (Treponema) isolates by restriction endonuclease analysis and DNA hybridization. 132 72


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