DNA polymerase epsilon, acetylases and remodellers cooperate to form a specialized chromatin structure at a tRNA insulator

EMBO J. 2009 Sep 2;28(17):2583-600. doi: 10.1038/emboj.2009.198. Epub 2009 Jul 23.


Insulators bind transcription factors and use chromatin remodellers and modifiers to mediate insulation. In this report, we identified proteins required for the efficient formation and maintenance of a specialized chromatin structure at the yeast tRNA insulator. The histone acetylases, SAS-I and NuA4, functioned in insulation, independently of tRNA and did not participate in the formation of the hypersensitive site at the tRNA. In contrast, DNA polymerase epsilon, functioned with the chromatin remodeller, Rsc, and the histone acetylase, Rtt109, to generate a histone-depleted region at the tRNA insulator. Rsc and Rtt109 were required for efficient binding of TFIIIB to the tRNA insulator, and the bound transcription factor and Rtt109 in turn were required for the binding of Rsc to tRNA. Robust insulation during growth and cell division involves the formation of a hypersensitive site at the insulator during chromatin maturation together with competition between acetylases and deacetylases.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Chromatin / chemistry*
  • Chromatin / metabolism
  • Chromatin Assembly and Disassembly
  • DNA Polymerase II / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism*
  • Histones / metabolism
  • Insulator Elements*
  • RNA, Transfer / genetics*
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Chromatin
  • DNA-Binding Proteins
  • Histones
  • RSC complex, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • RNA, Transfer
  • Histone Acetyltransferases
  • Rtt109 protein, S cerevisiae
  • DNA Polymerase II