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)

Chromatin assembly in a crude DEAE (CD) fraction from budding yeast is ATP dependent and generates arrays of physiologically spaced nucleosomes which significantly protect constituent DNA from restriction endonuclease digestion. The CD fractions from mutants harboring deletions of the genes encoding histone-binding factors (NAP1, ASF1, and a subunit of CAF-I) and SNF2-like DEAD/H ATPases (SNF2, ISW1, ISW2, CHD1, SWR1, YFR038w, and SPT20) were screened for activity in this replication-independent system. ASF1 deletion substantially inhibits assembly, a finding consistent with published evidence that Asf1p is a chromatin assembly factor. Surprisingly, a strong assembly defect is also associated with deletion of CHD1, suggesting that like other SNF2-related groups of nucleic acid-stimulated ATPases, the chromodomain (CHD) group may contain a member involved in chromatin reconstitution. In contrast to the effects of disrupting ASF1 and CHD1, deletion of SNF2 is associated with increased resistance of chromatin to digestion by micrococcal nuclease. We discuss the possible implications of these findings for current understanding of the diversity of mechanisms by which chromatin reconstitution and remodeling can be achieved in vivo.
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PMID:Replication-independent assembly of nucleosome arrays in a novel yeast chromatin reconstitution system involves antisilencing factor Asf1p and chromodomain protein Chd1p. 1458 55

Despite evidence that histone H3 and H4 proteins may act as the precursor for orientating the DNA sequence to form nucleosome structures, there is no direct evidence of the formed compact structure. Here, it is demonstrated that a histone H3-H4 octasome could be constructed without the involvement of histone H2A-H2B under in vitro reconstitution conditions. Atomic force microscopy was used to obtain the first direct observation of the octasome structure, which exhibited a similar core-protein size as that of a nucleosome but with a shorter core histone-binding DNA region. The octasome also displayed a one-step histone-dissociation pattern under heat treatment, distinct micrococcal nuclease and peplomycin accessibility, which suggests a different wrapping pattern to that in nucleosomes.
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PMID:Direct Observation of H3-H4 Octasome by High-Speed AFM. 3008 6