Histone acetyltransferase type B catalytic subunit (HAT1)

Acetylates soluble but not nucleosomal histone H4 at'Lys-5' (H4K5ac) and'Lys-12' (H4K12ac) and, to a lesser extent, acetylates histone H2A at'Lys-5' (H2AK5ac). Has inherent substrate specificity that modifies lysine in recognition sequence GXGKXG.

May be involved in nucleosome assembly during DNA replication and repair as part of the histone H3.1 and H3.