Critical determinants for chromatin binding by Saccharomyces cerevisiae Yng1 exist outside of the plant homeodomain finger.

The temporal and spatial regulation of histone post-translational modifications is essential for proper chromatin structure and function. The Saccharomyces cerevisiae NuA3 histone acetyltransferase complex modifies the amino-terminal tail of histone H3, but how NuA3 is targeted to specific regions of the genome is not fully understood. Yng1, a subunit of NuA3 and a member of the Inhibitor of Growth (ING) protein family, is required for the interaction of NuA3 with chromatin.

Histone acetylation: where to go and how to get there.

Transcriptionally active DNA is packaged with histones that are post-translationally acetylated on multiple lysines within their amino termini. While the majority of this acetylation is limited to the promoters of genes, acetylated histones are also found throughout transcribed units. Over the last decade we have uncovered many of the pathways involved in directing histone acetylation to active genes.

The Yng1p plant homeodomain finger is a methyl-histone binding module that recognizes lysine 4-methylated histone H3.

The ING (inhibitor of growth) protein family includes a group of homologous nuclear proteins that share a highly conserved plant homeodomain (PHD) finger domain at their carboxyl termini. Members of this family are found in multiprotein complexes that posttranslationally modify histones, suggesting that these proteins serve a general role in permitting various enzymatic activities to interact with nucleosomes. There are three members of the ING family in Saccharomyces cerevisiae: Yng1p, Yng2p, and Pho23p.