Sir2 and the acetyltransferase, Pat, regulate the archael chromatin protein, Alba.

Marsh VL, Peak-Chew SY, and Bell SD
Medical Research Council Cancer Cell Unit, Cambridge CB2 2XZ.

The DNA binding affinity of Alba, a chromatin protein of the archaeon Sulfolobus solfataricus P2, is regulated by acetylation of lysine 16. Here we identify an acetyl transferase that specifically acetylates Alba on this residue. The effect of acetylation is to lower the affinity of Alba for DNA. Remarkably, the acetyl transferase is conserved not only in archaea but also in bacteria, where it appears to play a role in metabolic regulation. Our data suggest therefore that S. solfataricus has co-opted this bacterial regulatory system to generate a rudimentary form of chromatin regulation. (added 2005/4/12)

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http://www.jbc.org/cgi/reprint/M501280200v1