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)

Previous studies have documented transcription initiation sites and nuclease hypersensitive sites upstream of the epsilon-globin canonical cap site in K562 cells. The upstream transcription initiation sites coincide with some of the nuclease hypersensitive sites. Comparison of the positions of the upstream transcription initiation and the nuclease hypersensitive sites with the nucleotide base order shows that these upstream sites fall significantly closer to poly (dA).poly (dT) tracts than can reasonably be accounted for by chance. It is concluded that these sites are related to the occurrence of poly (dA).poly (dT) tracts of at least five base pairs. Other studies have related some particular functional properties to poly (dA).poly (dT) tracts. Additionally, poly (dA).poly (dT) tracts have been shown to have unusual physical characteristics and to produce an intrinsic bending of the DNA molecules in which they are located. This study indicates that poly (dA).poly (dT) tracts can provide access to DNA for RNA polymerases and induce a DNA conformation recognized by DNase I or S1 nuclease.
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PMID:Transcription initiation and nuclease-sensitive sites upstream of the epsilon-globin gene in K562 cells are related to poly (dA).poly (dT) sequences. 225 7

We have mapped sites in chromatin flanking the epsilon-globin gene in the K562 cell which are hypersensitive to digestion with DNAseI, micrococcal nuclease and S1 nuclease. Many of those in the 5' flanking region correspond to minor upstream transcriptional starts. However, one prominent site occurs upstream of the boundary of transcription; it maps to a region with an unusual DNA sequence. In baby hamster kidney cells stably transformed with recombinant DNA containing the human epsilon-globin gene and in Cos 7 cells transiently transfected with DNA containing the epsilon-globin gene, hypersensitive sites can be demonstrated.
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PMID:The chromatin structure of the human epsilon globin gene: nuclease hypersensitive sites correlate with multiple initiation sites of transcription. 609 22

The human epsilon-globin gene was transcribed in vitro in isolated K562 cell nuclei by using exogenous Escherichia coli RNA polymerase (EC 2.7.7.6). Newly formed RNA transcripts were distinguished from nuclear RNA molecules by (i) incorporating mercurated UTP into RNA under conditions in which the endogenous polymerase II is inactive and (ii) subsequently isolating the mercurated RNA by affinity chromatography on thiolated Sepharose. A specific 5'-end-labeled probe spanning the epsilon-globin gene cap site was used in nuclease S1 mapping studies to examine the in vitro initiation site of the isolated transcripts. It was found that transcription occurred from the coding strand only and originated almost entirely from a point that was identical to that of the major cap site for epsilon-globin mRNA in vivo.
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PMID:Accurate initiation of human epsilon-globin RNA synthesis by Escherichia coli RNA polymerase in isolated nuclei of K562 erythroleukemia cells. 633 Jul 34

Analysis by the circular permutation assay of the human epsilon-globin gene region revealed that the DNA bend sites were located every 682.5 +/- 132.0 base pairs on average, separating the region into domains. Among 10 major and 1 minor bend sites mapped in the region, the transcription initiation and termination sites of the epsilon-globin gene were located close to the bend sites, and the first and the second exons of the epsilon-globin gene were separated from the third exon by another site. The bend sites were also located anterior to the two Alu family sequences. Short poly(dA).poly(dT) tracts typical for DNA bending were not always present in the sites. Fine mapping of a bend site having no poly(dA).poly(dT) tracts with concatenated oligonucleotides and analysis by S1 nuclease nicking assay indicated that the unusual structure, a base slippage or a partial triplex DNA structure, formed by a polypurine.polypyrimidine sequence in the region is the basis of bending. The bend sites were mapped in the promoter region (within approximately 300 base pairs from the cap site) of the human beta-globin and in c-myc and erythropoietin receptor genes, as well as in the mouse beta maj-globin gene. The conservation and the periodicity of the bend sites in the noncoding region suggest the active role of the sites that is a signal for nucleosome phasing.
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PMID:Periodicity of DNA bend sites in human epsilon-globin gene region. Possibility of sequence-directed nucleosome phasing. 807 50