SIR2, NAD-dependent histone deacetylase SIR2
Enzyme Classification 3.5.1.-
Also Known as
SIR2_YEAST, SIR2, MAR1
NAD-dependent deacetylase, which participates in a wide range of cellular events including chromosome silencing, chromosome segregation, DNA recombination and the determination of life span. Involved in transcriptional repression of the silent mating-type loci HML and HMR and telomeric silencing via its association with SIR3 and SIR4. Plays a central role in ribosomal DNA (rDNA) silencing via its association with the RENT complex, preventing hyperrecombination, and repressing transcription from foreign promoters, which contributes to extending life span. Probably represses transcription via the formation of heterochromatin structure, which involves the compaction of chromatin fiber into a more condensed form, although this complex in at least one case can still bind euchromatic levels of positive transcription regulators. Although it displays some NAD-dependent histone deacetylase activity on histone H3K9Ac and H3K14Ac and histone H4K16Ac in vitro, such activity is unclear in vivo and may not be essential. Homomultimer. Forms a complex with SIR3 and SIR4 (PubMed:9122169). Component of the RENT complex, at least composed of SIR2, CDC14 and NET1 (PubMed:10219244, PubMed:10219245). The RENT complex interacts with FOB1 (PubMed:12923057). Interacts with ESC8 (PubMed:12399377). Interacts with and ZDS2 (PubMed:10662670). Interacts with MCM10 (PubMed:16328881). Interacts with SLX5 (PubMed:18086879). Interacts with NSI1 (PubMed:22362748).