Abstract
A recent publication shows that a simple chemical event, acetylation of lysine 16 on the histone H4 N-terminal tail domain (NTD), completely abolishes the ability of the H4 NTD to mediate the nucleosome-nucleosome interactions involved in chromatin condensation. This result provides novel insight into the molecular mechanism of histone acetylation and also implicates H4 K16acet-dependent changes in chromatin fiber architecture as a central mechanism for generating transcriptionally active genomic domains.