In the SIR protein complex, SIR2 removes acetyl groups from the lysine on histone tails H3 and H4, [17] 'priming' the nucleosome for chromatin packaging by the SIR3 component of the complex.

2001年11月14日 · The modifications of histones, as well as reversible modifications of SIR proteins, may play an important role in the assembly of a nucleosome-SIR complex. Because the variant histone H2A.Z crosslinks to repressed domains, it …

The Sir complex creates structured chromosomal domains at telomeres, silent mating-type loci and ribosomal DNA to invoke these functional states.

2005年5月20日 · Our analysis of the assembly of Sir2, Sir3, and Sir4 into the SIR complex has revealed a role for active NAD-dependent substrate deacetylation in this process. We find that purified Sir proteins can assemble together into a stoichiometric complex.

The SIR genes are determinants of life span in yeast mother cells. Here we show that life span regulation by the Sir proteins is independent of their role in nonhomologous end joining.

The Sir complex represses transcription at telomeres, mating-type loci, and ribosomal DNA. Unlike SIR3 and SIR4, the SIR2 gene is highly conserved in organisms ranging from archaea to humans.

2001年11月1日 · The SIR (silent information regulator) genes in the yeast Saccharomyces cerevisiae encode a family of nuclear proteins that localize to specific genomic sequences and mediate the formation of a specialized chromatin structure …

2010年1月1日 · The Sir complex at these loci consists of Sir1, Sir2, Sir3, and Sir4p, with Sir1p playing a significant role in the establishment of HM locus silencing, variable roles at native telomeres, and only an indirect role at artificial truncated telomeres often used to study silencing.

2005年5月20日 · Assembly of silent chromatin domains in budding yeast involves the deacetylation of histone tails by Sir2 and the association of the Sir3 and Sir4 proteins with hypoacetylated histone tails.

2011年11月18日 · We report the crystal structure of the complex of the hypermorphic D205N Sir3 BAH domain (BAH Sir3) and the nucleosome core particle (NCP) at 3.0 Å resolution. Details of complex reconstitution, crystallization, data collection, and refinement can be found in the supporting online material (28).