Modification-binding domains interpret histone PTMs. Domains from various histone-interacting proteins are depicted along with the PTMs that they bind on histone H3. Multiple reading domains can interact with a single modified site, as illustrated for histones H3K4, K9, K27, and K36. Interactions may also change depending on the modification present at the site, as shown for acetylation or methylation of histones H3K9 and K36. The colors represent different PTMs and associated binding domains, which are depicted as follows: pink, methylation; green, acetylation.