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)

A discrete, 600-nucleotide-long plus-strand DNA has been identified among the products of reverse transcription by virions of Moloney murine leukemia virus. Its polarity was shown by hybridization to minus-strand DNA. It appears to be copied from the right end of minus-strand DNA because (i) its restriction endonuclease cleavage pattern corresponds to the redundant 600-base segment found at either end of the ultimate double-stranded reverse transcription products, (ii) its synthesis is actinomycin D sensitive, and (iii) its synthesis begins during the first hour of a reverse transcription reaction when only the right-hand end of minus-strand DNA is available as template. We therefore call this DNA plus-strong-stop DNA by analogy with the minus-strong-stop DNA copied from the left end of the viral RNA. Both strong-stop DNAs are made early during in vitro reactions and decline in concentration later, consistent with postulated roles as initiators of long minus- and plus-strand DNA. Unlike minus-strong-stop DNA, plus-strong-stop DNA remains as a double-stranded nucleic acid after its synthesis, as shown by S1 nuclease resistance. A primer to initiate plus-strong-stop DNA synthesis has not been identified; the product found thus far has no detectable RNA attached to it.
Proc Natl Acad Sci U S A 1979 Sep
PMID:Synthesis of a 600-nucleotide-long plus-strand DNA by virions of Moloney murine leukemia virus. 9 28

We have compared the amount of clustered and interspersed repetitive sequences in the genome of four Amphibia with different DNA contents per haploid nucleus: two Anura (Xenopus laevis, 3 pg and Bufo bufo, 7 pg) and two Urodela (Triturus cristatus, 23 pg and Necturus maculosus, 52 pg). High molecular weight DNA of the four species was denatured and reassociated to the same Cot in order to obtain duplex sequences with a similar reiteration frequency. Single-stranded DNA was digested off with the Aspergillus S1 nuclease. DNA was then fractionated according to the molecular weight through an agarose A-50 column. We found that the amount of long repetitive sequences is roughly proportional to the genome size in the four species, while the number of short (about 300 base pairs) repetitive sequences is increased many-fold in the species with the larger DNA content, both in Anura and in Urodela.
Biochim Biophys Acta 1978 Sep 27
PMID:Clustered and interspersed repetitive DNA sequences in four amphibian species with different genome size. 10 Dec 46

Aurintricarboxylic acid (ATA) is a general inhibitor of nucleases. ATA has been shown to inhibit the following enzymes in vitro: DNAse I, RNAse A, S1 nuclease, exonuclease III, and restriction endonucleases Sal I, Bam HI, Pst I and Sma I. The observed inhibition is consistent with the proposal by Blumenthal and Landers (BBRC 55, 680, 1973) that most nucleic acid binding proteins will be sensitive to ATA. The action of ATA as a nuclease inhibitor can be used to advantage in the isolation of cellular nucleic acids.
Nucleic Acids Res 1977 Sep
PMID:Use of aurintricarboxylic acid as an inhibitor of nucleases during nucleic acid isolation. 41 6

Uteroglobin, a progesterone-induced uterine protein of the rabbit, is synthesized in cell-free systems as a precursor containing 21 additional amino-acids at its N-terminal end. The mRNA for pre-uteroglobin has been purified from the membrane-bound polysomes of induced endometrium and used as template for the synthesis of a full copy complementary DNA. Final purification of the cDNA was based on hybridization to the template mRNA up to a low value of r0t (0.01 M . s) and digestion of the non-hybridized cDNA by S1 nuclease. A comparison of the hybridization kinetics of the pre-uteroglobin cDNA and rabbit globin cDNA to their respective templates indicates a nucleotide sequence complexity of 650 for pre-uteroglobin mRNA, in agreement with the values obtained by sucrose gradient centrifugation and polyacrylamide gel electrophoresis in formamaide. The melting temperature of the hybrids of pre-uteroglobin cDNA to its template reflects the absence of mismatched sequences. This cDNA has been used to quantify pre-uteroglobin mRNA sequences in the endometrial RNA from control animals and from animals treated sequentially with estradiol and progesterone. In agreement with the induction of uteroglobin-synthesizing activity, there is a dramatic increase in the uterine content of pre-uteroglobin mRNA after hormonal treatment. Part of this effect can be accounted for by hormonally induced cell proliferation. When expressed on a DNA basis there is a 50--100-fold increase in the cellular content of pre-uteroglobin mRNA following hormonal treatment.
Eur J Biochem 1979 Sep
PMID:Synthesis and characterization of a DNA complementary to pre-uteroglobin mRNA. 49 5

African swine fever virus DNA sediments in neutral sucrose density gradients as a single component with a sedimentation coefficient of 60S. In alkaline sucrose density gradients, this material shows two components with sedimentation coefficients of 85S and 95S, respectively. The sedimentation rate value of alkali-denatured virus DNA in neutral sucrose density gradients and the renaturation velocity of denatured DNA show that is reassociated much faster than expected from its genetic complexity. This behavior is compatible with the existence of interstrand cross-links in the molecule. We also present results which suggest that there are only a few such cross-links per molecule, that they are sensitive to S1 nuclease digestion, and that they are probably located next to the ends of the DNA.
J Virol 1979 Sep
PMID:Cross-links in African swine fever virus DNA. 51 89

The tRNA genes of bacteriophage T5 are located in four clusters on the continuous heavy DNA strand (Chen, M.-J., Locker, J., and Weiss, S.B. (1976) J. Biol. Chem. 251, 536--547). Three of the four clusters are within the DNA C segment; the fourth cluster, to which only tRNAArg has been localized, maps in a 3.02 kilobase (kb) region of which 1.99 kb are at the right end of the C segment and 1.03 kb at the left end of the D segment. In order to localize the tRNAArg gene further and to define its relationship to the C-D nick, we devised a suitable method for preparing T5 DNA fragments whose ends correspond to the position of the T5 DNA nicks contained in the light DNA strand. In this method, DNA is denatured, partially renatured, and digested with low concentrations of S1 nuclease. Agarose-gel electrophoresis of these digests gives a pattern of bands which correlate in size with the pattern expected from the nicked structure of T5 DNA. Annealing of individual purified T5 [35P]tRNA species to the T5 DNA fragments transferred to nitrocellulose filters shows that tRNAArg hybridizes exclusively to the D fragment and is therefore localized to 1.03 kb at the 5' (left) end of the heavy strand of the D segment. This finding suggests that the promotor for this early gene is to the right of the C-D nick in T5 DNA; hence, the C-D nick does not coincide with this early promotor.
J Biol Chem 1978 Sep 25
PMID:Localization of the arginine tRNA gene to the D segment of T5 bacteriophage DNA. A new procedure for producing duplex DNA fragments. 68 65

Predefined changes in a known DNA sequence were introduced by a general method. Oligodeoxyribonucleotides complementary to positions 582 to 593 of the viral DNA strand of the bacteriophage phiX174 am3 mutant (pGTATCCTACAAA), and to the wild type sequence in this region (pGTATCCTACAAA), were synthesized and used as specific mutagens. Each of these oligonucleotides was incorporated into a complete circular complementary strand when used as primer on a genetically heterologous viral strand template, by the combined action of subtilisin-treated Escherichia coli DNA polymerase I and T4 DNA ligase. Incomplete duplexes were removed or were inactivated by nuclease S1 and the products were used to transfect spheroplasts of E. coli. Both oligonucleotides induced specific mutations at high efficiency when used with heterologous template (15% mutants among progeny phage). The am phages isolated by this procedure are phenotypically gene E mutants, and contain A at position 587 of the viral strand. They thus appear identical with am3 and provide evidence that the change G leads to A at position 587 is sufficient to produce a defective E function. Since the template for the induction of am mutants carried another genetic marker (sB1), the strains carrying the induced mutations have the new genotype am3 sB1. It should be possible to introduce the am3 mutation into any known mutant strain of phi174 using this same oligonucleotide. Both possible transition mutations were induced in these experiments. In principle, the method could also induce transversions, insertions, and deletions. The method should be applicable to other circular DNAs of similar size, for example recombinant DNA plasmids.
J Biol Chem 1978 Sep 25
PMID:Mutagenesis at a specific position in a DNA sequence. 68 66

The mitochondrial DNA of the protozoan Leishmania tarentolae, known as kinetoplast DNA, contains thousands of minicircles linked in a two-dimensional network. When kinetoplast DNA from exponentially growing cells is centrifuged to equilibrium in a CsCl/ethidium bromide gradient, it is resolved into two discrete components, Form I and Form II. Nearly all of the minicircles in Form I networks are covalently closed and all of those in Form II networks are open. These forms are indistinguishable from each other when examined by electron microscopy and they appear identical when analyzed by gel electrophoresis after digestion with the restriction enzymes Hae III or Hpa II. However, Form II networks sediment roughly 50% faster than Form I networks on a neutral sucrose gradient, indicating that Form II networks are larger in size or more compact in conformation, or both. Analysis of denatured Form II DNA by sedimentation or electron microscopy indicates that nearly all of its minicircles have one or more interruptions in both strands. Since the majority of the Form II minicircles can be closed by DNA ligase, most of these interruptions must be nicks. Experiments with S1 nuclease indicate that some small gaps may also exist in Form II minicircles. 5'-Terminal nucleotide analysis of Form II kinetoplast DNA does not suggest that the interruptions are at specific locations in the minicircles. The significance of the two forms of kinetoplast DNA has not yet been determined, but it is possible that Form II is an intermediate in replication of this DNA.
J Biol Chem 1977 Sep 10
PMID:A nicked form of kinetoplast DNA in Leishmania tarentolae. 89 2

The sequence organization of the DNA of the mollusc Aplysia californica has been examined by a combination of techniques. Close-spaced interspersion of repetitive and single copy sequences occurs throughout the majority of the genome. Detailed examination of the DNA of this protostome reveals great similarities to the pattern observed in the two deuterostome organisms previously examined in detail in this laboratory, Xenopus laevis and Strongylocentrotus purpuratus. Labeled and unlabeled Aplysia DNA were prepared from developing embryos and sheared to a fragment length of 400 nucleotides. The kinetics of reassociation were studied by means of hydroxyapatite chromatography, single-strand-specific S1 nuclease, and optical methods of assay. Aplysia DNA of this fragment length contains at least five resolvable kinetic fractions. One classification of these fractions, listed with their reassociation rate constants (l M-1 sec-1) is: single copy (0.00057), slow (0.047), fast (2.58), very fast (4000), and foldback (greater than 10(5)). Sequence arrangement was deduced from: the kinetics of reassociation of DNA fragments of length 400 or 2000 nucleotides; the hyperchromicity of reassociated fragments containing duplex regions; the size of duplex regions resistant to S1 nuclease; and the reassociation of labeled fragments of various lengths with short driver fragments. More than 80% of the single copy DNA sequences are interspersed with repetitive sequences. The maximum spacing of the repeats is about 2000 nucleotides, and the average less than 1000. The very fast fraction does not show interspersion with single copy sequences or with other kinetic fractions. The foldback fraction sequences are fairly widely interspersed. The slow fraction sequences are interspersed with the fast fraction, and possibly also with the single copy DNA. The fast fraction is the dominant interspersed repetitive fraction. Its sequences are adjacent to the great majority of the single copy sequences and have an average length of about 300 nucleotides.
Cell 1975 Sep
PMID:DNA sequence organization in the mollusc Aplysia californica. 116 33

If micrococcal nuclease is allowed to digest chromatin as it exists inside intact nuclei isolated from mouse myeloma tissue culture cells, more than 60% of the DNA can be isolated as a homogeneous fragment on a sucrose gradient. Analytical ultracentrifugation indicates that the protected DNA is native, unnicked, and about 140 +/- 10 base pairs long. After less extensive nuclease digestion, the protected DNA migrates in gels in lengths which are integral multiples of this 140 base pair "monomer" band. A submonomer band, 105 "/- 10 base pairs long, can also be detected. Similar digestion patterns were obtained by two different nuclear isolation procedures and even when intact cells were gently lysed directly in the digestion medium. These results confirm and extend the chromatin digestion studies of previous investigators and provide support for a subunit model for eukaryotic chromatin. The single strand specific S1 nuclease did not digest intranuclear chromatin under the conditions used.
Chromosoma 1975 Sep 26
PMID:Evidence for a subunit structure of chromatin in mouse myeloma cells. 117 64


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