Core histone macro-H2A, macro domain (IPR035796)

Short name: Macro_H2A

Overlapping homologous superfamilies


Domain relationships

  • Macro domain (IPR002589)
    • Core histone macro-H2A, macro domain (IPR035796)


MacroH2A is a variant of the major-type core histone H2A which contains an N-terminal H2A domain and a C-terminal nonhistone macro domain. Histone macroH2A is enriched on the inactive X chromosome of mammalian female cells [PMID: 11433014]. It does not bind poly ADP-ribose, but does bind the monomeric SirT1 metabolite O-acetyl-ADP-ribose (OAADPR) with high affinity through its macro domain [PMID: 15965484]. In addition, the macro domain of macroH2A associates with histone deacetylases and affects the acetylation status of nucleosomes. MacroH2A-containing nucleosomes are repressive toward transcription [PMID: 16107708].

The macro domain is a high-affinity ADP-ribose binding module found in a variety of proteins as a stand-alone domain or in combination with other domains like in histone macroH2A and some PARPs (poly ADP-ribose polymerases). Some macro domains recognize poly ADP-ribose as a ligand. Previously identified as displaying an Appr-1"-p (ADP-ribose-1"-monophosphate) processing activity, the macro domain may play roles in distinct ADP-ribose pathways, such as the ADP-ribosylation of proteins, an important post-translational modification which occurs in DNA repair, transcription, chromatin biology, and long-term memory formation, among other processes [PMID: 15902274].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.