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DNA compaction by the higher-order assembly of PRH/Hex homeodomain protein oligomers\ud

By Abdenour Soufi, Anyaporn Sawasdichai, Anshuman Shukla, Peter Noy, Tim Dafforn, Corinne J. Smith, Padma-Sheela Jayaraman and Kevin Gaston


Protein self-organization is essential for the establishment and maintenance of nuclear architecture and for the regulation of gene expression. We have shown previously that the Proline-Rich Homeodomain protein (PRH/Hex) self-assembles to form oligomeric complexes that bind to arrays of PRH binding sites with high affinity and specificity. We have also shown that many PRH target genes contain suitably spaced arrays of PRH sites that allow this protein to bind and regulate transcription. Here, we use analytical ultracentrifugation and electron microscopy to further characterize PRH oligomers. We use the same techniques to show that PRH oligomers bound to long DNA fragments self-associate to form highly ordered assemblies. Electron microscopy and linear dichroism reveal that PRH oligomers can form protein–DNA fibres and that PRH is able to compact DNA in the absence of other proteins. Finally, we show that DNA compaction is not sufficient for the repression of PRH target genes in cells. We conclude that DNA compaction is a consequence of the binding of large PRH oligomers to arrays of binding sites and that PRH is functionally and structurally related to the Lrp/AsnC family of proteins from bacteria and archaea, a group of proteins formerly thought to be without eukaryotic equivalents. \u

Topics: QH
Publisher: Oxford University Press
Year: 2010
OAI identifier:

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  26. (2009). Reconstitution of yeast silent chromatin: multiple contact sites and O-AADPR binding load SIR complexes onto nucleosomes in vitro. doi
  27. (2007). Repression by Groucho/TLE/Grg proteins: genomic site recruitment generates compacted chromatin in vitro and impairs activator binding in vivo. doi
  28. (2002). SATB1 targets chromatin remodelling to regulate genes over long distances. doi
  29. (2006). Structural insight into gene transcriptional regulation and effector binding by the Lrp/AsnC family. doi
  30. (2007). Structure of the Escherichia coli leucine-responsive regulatory protein Lrp reveals a novel octameric assembly. doi
  31. (2009). The logic of chromatin architecture and remodelling at promoters. doi
  32. (2008). The major architects of chromatin: architectural proteins in bacteria, archaea and eukaryotes. doi
  33. (2001). The molecular biology of the SIR proteins. doi
  34. (2009). The PRH/Hex repressor protein causes nuclear retention of Groucho/TLE co-repressors. doi
  35. (2004). The proline-rich homeodomain protein recruits members of the Groucho/Transducin-like enhancer of split protein family to co-repress transcription in hematopoietic cells. doi
  36. (1994). The Surf-1 and Surf-2 genes and their essential bidirectional promoter elements are conserved between mouse and human. doi
  37. (2007). The third dimension of gene regulation: organization of dynamic chromatin loopscape by SATB1. doi
  38. (2003). The transcriptional repressor protein PRH interacts with the proteasome. doi
  39. (2003). Transcriptional repression in eukaryotes: repressors and repression mechanisms. Cell Mol. doi
  40. (1994). YY1 is involved in the regulation of the bi-directional promoter of the Surf-1 and Surf-2 genes. doi

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