A large body of evidence suggest that reversible post-translational modifications (PTMs) of histones play a crucial role in gene expression and to the field of epigenetics, and that aberrant histone modification contributes to different diseases such as cancer. Recently, two novel types of histone PTMs called lysine malonylation (Kmal) and succinylation (Ksucc) have been identified. KMal and Ksucc induce more substantial chemical changes to the chemical properties of the modified protein than lysine acetylation or methylation, which are already known to have very important cellular roles. Taking into account the fact that most previously described histone PTMs have important biological functions and are implied in different human diseases, a logical hypothesis is that Ksucc and Kmal also play an important role in the regulation of histone protein structure and function, and potentially also across the wider proteome. These novel PTMs open many interesting questions:• Which histone lysine residues are the targets for these novel PTMs?• What enzymes regulate addition (writer) or removal (eraser) of Kmal and Ksucc?• Are there reader proteins that bind to histone Kmal and Ksucc to modulate changes in gene transcription?• What role do histone Kmal and Ksucc play in the regulation of histone structure and function?However, there are no standard and robust tools to directly identify and manipulate the enzymes or binders, and identifying the targets is currently a massive undertaking, and it is not easy to ‘pulse-chase’ without a label. The aim of the proposed project is to develop a platform of chemical probes and technologies that will enable for the first time proteome-wide global analysis of the complex biological network involve in these new types of PTMs of histone. These novel chemical biology tools will be used to identify novel histone targets and the enzymes (writers and erasers) and proteins (readers) involved in these new PTMs.