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)

Brief micrococcal nuclease digestion of chick embryonic red blood cells results in preferential excision and solubilization of monomer nucleosomes associated with beta-globin sequences and also 5'-sequences flanking the beta-globin gene. Both regions are DNAse-I sensitive in nuclei. Such salt-soluble nucleosomes are enriched in all four major HMG proteins but HMG1 and 2 are only weakly associated. These nucleosomes appear to have lost much of the DNAse-I sensitivity of active genes. The HMG14 and 17-containing salt-soluble nucleosomes separated by electrophoresis are not DNAse-I sensitive and contain inactive gene sequences as well as active sequences. Reconstitution of HMG proteins onto bulk nucleosomes or chromatin failed to reveal an HMG-dependent sensitivity of active genes as assayed by dot-blot hybridization and it was found that the DNAse-I sensitivity of ASV proviral sequences as assayed by dot-blot hybridization was not HMG-dependent. These results indicate that higher order chromatin structures might be responsible for nuclease sensitivity of active genes.
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PMID:The nuclease sensitivity of active genes. 630 Jul 66