Compensatory Interactions between Sir3p and the Nucleosomal LRS Surface Imply Their Direct Interaction
2008

Understanding the Interaction Between Sir3p and Nucleosomal LRS Surface

Sample size: 109 publication 10 minutes Evidence: high

Author Information

Author(s): Norris Anne, Bianchet Mario A., Boeke Jef D.

Primary Institution: Johns Hopkins University School of Medicine

Hypothesis

The LRS surface of the nucleosome is a binding site for a trans-acting silencing factor, and this interaction might be electrostatic in nature.

Conclusion

The study provides genetic evidence that the Sir3p BAH domain directly binds the LRS domain, suggesting an electrostatic model for their interaction.

Supporting Evidence

  • The LRS domain is crucial for silencing at ribosomal DNA and telomeres.
  • Mutations in histones H3 and H4 were identified as suppressors of the H3 A75V allele.
  • Sir3p BAH domain mutations restored binding to telomeric DNA in LRS mutants.

Takeaway

Scientists studied how a part of DNA called the LRS interacts with a protein named Sir3p, finding that changes in their electrical charges affect their ability to silence genes.

Methodology

The researchers performed an EMS mutagenesis screen to identify suppressors of the H3 A75V LRS allele and characterized mutations in histones and the Sir3 protein.

Limitations

The study primarily focuses on specific mutations and may not account for all possible interactions affecting silencing.

Digital Object Identifier (DOI)

10.1371/journal.pgen.1000301

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