The DNA of cells containing nuclei (eukaryotic cells) is tightly associated with

Question

The DNA of cells containing nuclei (eukaryotic cells) is tightly associated with proteins called histones, most of which are rather basic proteins (i.e., they have high isoelectric points). Considering the basic character of most histones and the amino acids that contribute to this basic character, what enzymes would probably be most effective in disrupting histones from eukaryotic cellular DNA? Would you expect the procedure used in this experiment for the isolation of bacterial DNA to be useful for the isolation of DNA from eukaryotic cells?

Explanation / Answer

Eukaryotic cells contain five different kinds of histone H1, H2A, H2B, H3, H4. The mass of DNA in eukaryotic nuclei is equal to the mass of histones. It consist 20 percent of their amino acids are arginine or lysine. They can be extracted from cells with strong acids, such as 1.5 N HCL conditions that would destroy most proteins. The histones migrate toward the cathode during nondenaturing electrophoresis, unlike most other proteins, which are acidic and therefore move toward the anode.

Nucleosome remodelling agents such as SW1/SNF and ISWI are required for activation of some genes. These proteins disrupt the core histones in nucleosomes, and may also move nucleosomes. Such remodelling, combined with core histone acetylation and binding of other proteins, can create nucleosome free enhancers that can bind readily to transcription activators.

Histone acetyl transferase (HAT) enzyme plays a key role disrupting the histones from the DNA.Histone acetylation occurs in both the cytoplasm and nucleus. Cytoplasmic acetylation is carried out by a HAT B and prepares histones for incorporation into nucleosomes. The acetyl groups are later removed in the nucleus. Nucleur acetylation is catalzsed by a HAT A and correlates with transcription activation.

I thought that there is not possible to isolation of bacterial DNA like eukaryotic DNA isolation procedure.

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