Multiple interfaces to recognize nucleosomal targets.

In eukaryotic cells, DNA is tightly compacted as chromatin. Chromatin states must be dynamically changed to increase the accessibility of transcription factors (TFs) to chromatin or to stably silence genes by higher-order chromatin structures known as heterochromatin. The regulation of chromatin needs cooperative action performed by a variety of proteins. Specific binding of TFs to target DNA is the initial step of chromatin regulation and promotes changes in the post-translational modifications of histone tails, which themselves are recognized by a set of histone reader proteins. Recent biochemical studies have revealed that some TFs that recognize specific DNA sequences can also interact with histones. Furthermore, histone reader proteins that recognize specific histone tail modifications have been shown to have the ability to directly bind to DNA. In this commentary, we introduce recent advances in the elucidation of how chromatin regulating factors recognize nucleosomal targets.