New functions for an ancient domain

Macrodomains function as binding modules for metabolites of NAD(+), including poly(ADP-ribose). Three new studies explore how binding of poly(ADP-ribose) by the macrodomains of histone variant macroH2A1.1 and the ATP-dependent chromatin-remodeling protein ALC1 (also called CHD1L) leads to the modulation of chromatin structure, regulating nuclear functions such as DNA-damage detection and repair.