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). Homotetramer (PubMed:26921242). Component of the CENP-A recruiting complex composed of at least mis16, mis19, mis19 and mis20 (PubMed:15369671, PubMed:24774534, PubMed:24789708, PubMed:25375240). Belongs to the mis18 family.