Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DNA replication has been studied in in vitro cultured bovine liver cells permeabilized in 0.02% Triton X-100. The Km for TTP was 20 microM. The initial incorporation rate at 10 microM TTP concentration was about 12% of the in vivo synthesis and declined very strongly within 1 h. A similar decline of the incorporation rate was found at 0.12 microM TTP concentration. DNAase I digestion of DNA-matrix complexes obtained from isolated nuclei in 2 M NaCl revealed that newly replicated DNA was preferentially bound to the nuclear matrix. A similar digestion with S1 nuclease caused a selective release of short duplexes of Okazaki fragments with the complementary parental strand. The results show that in vivo replication continues in permeabilized cells in an almost unchanged way, except for a gradual decline of its rate which is mainly due to inactivation of one or more essential components.
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PMID:In vitro DNA replication in association with the nuclear matrix of permeable mammalian cells. 647 19

In a new combination of techniques for ribosomal RNA hybridization, complementary DNA is synthesized on 25S ribosomal RNA fragments generated by mild alkali treatment, by the enzymatic addition of polyadenylic acid tails, hybridization of these tails with oligo deoxyribosylthymine, and reverse transcription in the presence of tritiated TTP. Hybridization reactions are performed in solution. Heteroduplexes are collected on diethylaminoethylcellulose filter discs after treatment with S1 nuclease. The problems presented by secondary rRNA structure are avoided by denaturation before reverse transcription and before hybridization. The high percentage of duplex formation (78-87%), the low standard deviation of relative binding (averaging +/- 1.30% relative binding), and small differences in reciprocal hybridizations (1.71-5.18% relative binding), as well as the elimination of complications resulting from differences in the number of rRNA cistrons in nuclear DNA, make this method preferable to the membrane-filter technique commonly used in phylogenetic classifications based on the homology of large rRNAs.
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PMID:Complementary DNA-25S ribosomal RNA hybridization: an improved method for phylogenetic studies. 668 74