Article
- The EMBO Journal (2001) 20, 4522 - 4535
- doi:10.1093/emboj/20.16.4522
Sir2p exists in two nucleosome-binding complexes with distinct deacetylase activities
Sonja Ghidelli1, David Donze1, Namrita Dhillon1 and Rohinton T. Kamakaka1
- Unit on Chromatin and Transcription, NICHD/NIH, Building 18T, Room 106, 18 Library Drive, Bethesda, MD 20892, USA
Correspondence to:
Rohinton T. Kamakaka, E-mail: Rohinton@helix.nih.gov
Received 19 February 2001; Accepted 27 June 2001; Revised 18 June 2001
Abstract
The absolute requirement for the histone deacetylase activity of Sir2p in silencing coupled with the conservation of Sir2p-like proteins in larger eukaryotes suggests that this molecule plays an important role in gene regulation in all organisms. Here we report the purification and characterization of two Sir2p-containing protein complexes; one of which contains Sir4p and the other Net1p. The Sir4p-containing complex has an NAD-dependent histone deacetylase activity, while the Net1p-containing complex possesses deacetylase activity but only weak NAD-dependent histone deacetylase activity. Finally, we demonstrate that the Sir2p-containing complexes bind nucleosomes efficiently and partially restrict accessibility of the linker DNA to enzymatic probes.
Keywords:
- NET1,
- nucleosome,
- SIR2,
- SIR3,
- SIR4
