Regulatory subunit of the histone acetylase B (HAT-B) complex (By similarity). The complex acetylates 'Lys-12' of histone H4 which is required for telomeric silencing (By similarity). Component of the CENP-A recruiting complex that ensures the integrity of mitotic spindles through maintenance of kinetochore factors mis6/CENP-I and cnp1/CENP-A (PubMed:15369671, PubMed:24774534, PubMed:24789708, PubMed:25375240). Maintains the deacetylated state of histones specifically in the central core of the centromeres (PubMed:15369671). Component of the HAT-B complex composed of at least hat1 and hat2. The HAT-B complex binds to histone H4 tail (By similarity). Component of the CENP-A recruiting complex composed of at least mis16, mis19, mis19 and mis20 (PubMed:24774534, PubMed:24789708, PubMed:25375240). Belongs to the WD repeat RBAP46/RBAP48/MSI1 family.