Evidence that ubiquitylated H2B corrals hDot1L on the nucleosomal surface to induce H3K79 methylation

The ubiquitylation of histone H2B on lysine 120 is an important modification with roles in a diverse range of nuclear processes. Here, the authors use 'designer' chromatin to show that H2B-ub orients hDot1L into the correct position for activation.