Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.31.1 (micrococcal nuclease)
 2,818 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have investigated chromatin organization over the MMTV LTR, a promoter regulated by steroid hormones. The studies were performed on cell lines containing BPV-based episomal constructs. Nucleosome positioning was determined by localization of sites sensitive to the enzyme micrococcal nuclease, or to the chemical MPE-Fe(II). Experiments with both reagents indicate that nucleosomes are specifically positioned in MMTV LTR chromatin. In the absence of hormone a regular cutting pattern is obtained, with cleavage sites at +136, -60, -250, -444, -651, -826 and -1019 relative to the Cap site. In the presence of hormone the cutting pattern is unchanged, except for a region between -60 and -250 that becomes hypersensitive to MPE-Fe(II). This region contains the DNA sequences to which steroid receptor complexes bind during transcriptional activation. Our results indicate that this region is associated in chromatin from uninduced cells with a macromolecular complex (probably a nucleosome core), and this complex is displaced (or modified) upon binding of activated receptor.
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PMID:Sequence-specific positioning of nucleosomes over the steroid-inducible MMTV promoter. 282 86

The 15s globin mRNA-protein complex (mRNP) was isolated from chicken reticulocyte polyribosomes dissociated in EDTA. To determine protein binding sites, the mRNP was treated with micrococcal nuclease and the nuclease resistant RNA was mapped to the beta globin gene at the nucleotide level. As far as we can determine there is no bound protein from the Cap site to the poly A addition site of beta globin mRNA in the mRNP except for a short area in the coding region near the translation initiation site.
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PMID:Chicken reticulocyte polysomal messenger RNA-protein complex: absence of bound proteins in most of the coding region of beta globin mRNA. 646 16