Succinylation is a posttranslational modification where a succinyl group is added to a lysine residue of a protein molecule. This modification is found in many proteins, including histones. The potential role of succinylation is under investigation, but as addition of succinyl group changes lysine's charge from +1 to −1 and introduces a relatively large structural moiety , bigger than acetylation or methylation , it is expected to lead to more significant changes in protein structure and function.