Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

mRNA that encodes the common peptide precursor for the hormones corticotropin and beta-lipotropin was purified from the neurointermediate lobe of bovine pituitaries, and double-stranded cDNA species synthesized from this template were cloned in Escherichia coli X1776 by inserting them into the Pst I endonuclease cleavage site of the pBR322 plasmid using poly(dG)poly(dC) homopolymeric extensions. Certain of the cloned cDNA inserts contain nucleotides corresponding to the complete amino acid sequence of bovine corticotropin and a coding sequence that corresponds to at least the first portion of bovine beta-lipotropin. The nucleotide sequences coding for corticotropin and beta-lipotropin are separated on the cDNA by a 6-base-pair sequence encoding lysine and arginine, indicating that the carboxyl terminus of corticotropin is connected on the precursor peptide with the amino terminus of beta-lipotropin by these two amino acids. In addition, the cloned cDNA insert is characterized by an unusually high C+G nucleotide base content as well as by a number of DNA sequence duplications.
Proc Natl Acad Sci U S A 1978 Dec
PMID:Construction of bacterial plasmids that contain the nucleotide sequence for bovine corticotropin-beta-lipotropin precursor. 21 7

The covalently closed form of circular duplex SV40 DNA was separated from the open and linear form of SV40 DNA by agarose gel electrophoresis in a large-scale gel system. The closed circular DNA was recovered from agarose gels by re-electrophoresing the gel slices. The recovery of DNA was about 70%. Electron microscopic analysis showed that the recovered DNA did not have doube- or single-stranded breaks. The recovered DNA can be used without further purification for electron microscopy, as a substrate for experiments using restriction endonuclease and as a template for in vitro RNA synthesis.
Acta Med Okayama 1978 Dec
PMID:A simple large-scale method for separating closed circular form DNA by gel electrophoresis. 21 25

The cellular sites of integration of avian sarcoma virus (ASV) have been examined in clones of duck embryo cells infected with the Bratislava 77 strain of ASV using restriction endonuclease digestion, agarose gel electrophoresis, Southern blotting, and hybridization with labeled ASV complementary DNA probes. DNA prepared from 11 clones of duck embryo cells infected with the Bratislava 77 strain of ASV was digested with the restriction enzymes HpaI, which cleaves once within the viral genome, and Hind III, which cleaves twice within the viral genome, and the virus-cell DNA juncture fragments were resolved by agarose gel electrophoresis. Analysis of the virus-cell junctures present in individual ASV-infected duck embryo clones revealed that all clones contain at least one copy of nondefective proviral DNA with some clones containing as many as 5 to 6 copies of proviral DNA. A comparison of the virus-cell juncture fragments present in different ASV-infected clones showed that each clone contains a unique set of virus-cell junctures. These data suggest that ASV DNA can integrate at multiple sites within the duck embryo cell genome and that these sites appear to be different as defined by digestion with the restriction enzymes HpaI and HindIII.
J Virol 1979 Dec
PMID:Analysis of cellular integration sites in avian sarcoma virus infected duck embryo cells. 22 65

Extrachromosomal DNA purified from mink cells acutely infected with the Snyder-Theilen strain of feline sarcoma virus (FeSV) was digested with restriction endonucleases, and the DNA fragments were electrophoretically separated, transferred to a solid substrate, and hybridized with radiolabeled DNA transcripts complementary to different portions of the FeSV RNA genome. Major DNA species 8.4 and 5.0 kilobase pairs (kbp) long represent the linear, unintegrated proviruses of Snyder-Theilen feline leukemia virus and FeSV, respectively. Transfection experiments performed with electroeluted DNAs showed that the 8.4-kbp form led to the production of replicating nontransforming virus in mink and cat cells; in contrast, the 5.0-kbp DNA produced helper virus-independent foci of transformation in mouse NIH/3T3 cells and helper virus-dependent foci in mink cells at an efficiency comparable to that obtained with unfractionated extrachromosomal DNA. Sites of restriction endonuclease cleavage for six enzymes were oriented with respect to one another within the FeSV provirus. EcoRI recognized cleavage sites at 0.3 to 0.4 kbp from each terminus of FeSV DNA, reducing the 5.0-kbp DNA to molecules 4.3 kbp long; this enzyme excised a large internal proviral DNA fragment of corresponding size from the DNA of FeSV-transformed mink nonproducer cells. By using DNA transcripts complementary to different portions of the FeSV genome, sarcoma-specific sequences (the FeSV src gene) were positioned within 2.1 and 3.4 kbp from the 5' end of the proviral DNA with respect to the viral RNA genome. The src gene is flanked at both ends by sequences shared in common with feline leukemia virus. The localization of src sequences to this region suggests that a portion of an FeSV polyprotein which contains feline oncornavirus-associated cell membrane antigen (FOCMA-S) is the major product of this gene.
J Virol 1979 Dec
PMID:Restriction endonuclease mapping of unintegrated proviral DNA of Snyder-Theilen feline sarcoma virus: localization of sarcoma-specific sequences. 22 70

A plaque morphology mutant (pm-522) of human papovavirus BK, which was rescued from a human papovavirus BK-induced hamster pineocytoma, was characterized and compared with a cloned wild-type virus (wt-501). Mutant pm-522 formed turbid plaques and grew more slowly than wt-501 in human embryonic kidney (HEK) cells. The immunofluorescence assay revealed that more HEK cells underwent abortive infection with pm-522 than with wt-501. Whereas wt-501 induced brain tumors and osteosarcomas, but no insulinomas, in hamsters, pm-522 induced brain tumors and insulinomas. The DNA of pm-522 was found by electrophoresis and electron microscopy to have a deletion (85 +/- 15 base pairs) and an insertion (40 +/- 10 base pairs) between map coordinates 0.708 and 0.725 from the endonuclease EcoRI cleavage site. These results demonstrate the presence of a viable deletion human papovarivus BK mutant capable of inducing insulinomas in hamsters.
J Virol 1979 Dec
PMID:Viable deletion mutant of human papovavirus BK that induces insulinomas in hamsters. 22 73

We have developed a structurally unique probe which can be used to determine the chromosomal location of nonreiterated genes in vertebrate organisms by the method of in situ hybridization. The probe consists of several specific RNA molecules attached by means of poly(A) . poly(BrdUrd) hybrids to 125I-labeled DNA of high molecular weight. The probe can be synthesized with a variety of RNA molecules, giving it versatility for detecting a variety of genes irrespective of gene size, copy frequency, and host genome complexity. Using this probe prepared with retrovirus genomic RNAs, we have physically mapped all three detectable endogenous genomes of Rous-associated virus type 0 (RAV-0) in Spafas gs- chf- (group-specific antigen negative, chicken helper factor negative) chicken fibroblasts to specific sites on chromosome 1. This finding suggests that these multiple nontranscribed RAV-0 genomes evolved through gene duplication of an original RAV-0 genome. The endogenous src gene coding for a 60,000-dalton protein also has been localized to one of the small macrochromosomes, 10, 11, or 12, in both chicken and Japanese quail cells. The results presented here are consistent with and greatly extend previously reported data obtained by using both chromosome fractionation and restriction endonuclease techniques and thus support the soundness of this hybridization approach.
Proc Natl Acad Sci U S A 1979 Dec
PMID:Chromosome 1 contains the endogenous RAV-0 retrovirus sequences in chicken cells. 23 May 12

We have developed a theory to estimate the degree of sequence divergence between related DNAs from the comparison of restriction endonuclease recognition sites. Two major improvements have been made upon a similar method reported by Upholt (1977). First, the most probable value is calculated by the collective use of all available data. This reduces intrinsic statistical error and extends the analyzable range of sequence divergence. Second, all variables are redefined so that they have strict mathematical implications. This corrects a serious error arising from the misinterpretation of the meaning of the fraction of conserved cleavage sites. With this refined method, sequence divergence between rat and mouse mitochondrial DNAs (mtDNAs) was calculated to be about 25% substitutions/nucleotide, which is in good agreement with the DNA-DNA hybridization data obtained by Jakovcic et al. (1975). It was also estimated that the three types of rat mtDNAs differ from one another by 0.3 approximately 1% of total base pairs. These values are 2 approximately 5 times smaller than those obtained with the conventional method.
J Mol Evol 1979 Dec
PMID:An improved method for estimating sequence divergence between related DNAs from changes in restriction endonuclease cleavage sites. 23 86

A procedure is presented, that has allowed the rapid assignment of transposon Tn1 and Tn7 insertion sites in the large (130 Md) nopaline Ti-plasmid pTiC58, to specific restriction enzyme fragments. Total bacterial DNA is isolated from Agrobacterium tumefaciens strain C58 mutants that carry a transposon in their Ti-plasmid, and digested with an appropriate restriction endonuclease. The fragments are separated on an agarose gel, denatured and transferred to nitrocellulose filters. These are hybridized against purified wild type pTiC58, or against segments of PTiC58, cloned in E. coli using pBR322 as a vector plasmid. DNA sequences homologous to the probe are detected by autoradiography, thus generating a restriction enzyme pattern of the plasmid from a digest of total bacterial DNA. Mutant fragments can be readily identified by their different position compared to a wild type reference. This protocol eliminates the need to separate the large plasmid from chromosomal DNA for every mutant. In principle, it can be applied to the restriction enzyme analysis of insertion or deletion mutants in any plasmid that has no extensive homology with the chromosome.
Nucleic Acids Res 1979 Dec 11
PMID:Rapid mapping of transposon insertion and deletion mutations in the large Ti-plasmids of Agrobacterium tumefaciens. 23 64

The relationship between pyrimidine dimers (measured as endonuclease-sensitive sites) and newly-synthesized DNA has been examined in several different ways, with the following results:- 1. After UV-irradiation of normal human fibroblasts the frequency of pyrimidine dimer sites in sections of DNA which have been synthesized immediately before the UV-irradiation is similar to that in the bulk DNA. 2. The frequency of pyrimidine dimer sites in the parental strands of replicating DNA in UV-irradiated normal human fibroblasts is similar to that in the bulk DNA. 3. In UV-irradiated XP variant cells the size of DNA synthesized in the presence of caffeine immediately after UV irradiation accurately corresponds with the average interdimer distance in the parental DNA. This suggests that in this experimental situation each pyrimidine dimer gives rise to a disocntinuity or a termination site in the daughter strand.
Nucleic Acids Res 1979 Dec 11
PMID:The relationship between pyrimidine dimers and replicating DNA in UV-irradiated human fibroblasts. 23 65

Double-stranded RNA inhibits protein synthesis in at least two ways. It activates a protein kinase that blocks peptide chain initiation by phosphorylating the peptide chain initiation factor eIF-2 and also activates an endonuclease that inactivates different mRNAs at different rates. The protein kinase and the endonuclease have been partially purified from interferon-treated Ehrlich ascites tumor cells. The 2',5'-oligoadenylates [pppA(2'p5'A)n], found found earlier to be mediators in the activation of the endonuclease by double-stranded RNA, are not mediators in the activation of the protein kinase by double-stranded RNA.
Proc Natl Acad Sci U S A 1978 Dec
PMID:Interferon action: two distinct pathways for inhibition of protein synthesis by double-stranded RNA. 28 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>