Functions as an ATP-dependent nucleosome disassembly factor that helps evict canonical histone H3 from the 5'-end of genes upon their induction (PubMed:25406467). Also contributes to kinetochore assembly by cooperating with SCM3 to load the histone H3 variant CSE4/CENP-A at centromeres (PubMed:32079723). Provides a chromatin boundary function at the 5'-end of genes that restricts access by RTT106 and thus prevents ectopic spreading of repressive chromatin into coding regions (PubMed:19683497, PubMed:25406467, PubMed:22156209). Also prevents heterochromatin spreading downstream of the silent mating-type locus HMR, this function is independent of the tRNA boundary element (PubMed:16079223). Contributes to appropriate cell cycle regulation of histone gene expression by recruiting RNA polymerase II to histone genes, and subsequent CDK1- and casein kinase II-dependent eviction from chromatin is required to promote transcriptional elongation (PubMed:22156209). Interacts with CSE4/CENP-A (PubMed:32079723). Interacts with SCM3 (PubMed:32079723). Interacts with SPT16 (PubMed:22156209). Interacts with POB3 (PubMed:22156209). Interacts with the casein kinase II complex subunits CKA1, CKA2, CKB1 and CKB2 (PubMed:22156209). Interacts with RNA polymerase II (PubMed:22156209). Interacts (via Bromo domain) with histone H3 (PubMed:16079223). Interacts (via Bromo domain) with histone H4 (PubMed:16079223). Binds near the 5'-end within protein-coding genes (PubMed:25406467, PubMed:19683497). Localizes to the negative regulatory element NEG and promoter of the HTA1 gene during G2 and M-phase, and its open reading frame during G1/S (PubMed:22156209, PubMed:19683497). Phosphorylated by CDK1 and casein kinase II during S-phase, which leads to its eviction from histone gene promoters and promotes histone gene transcription. Decreases the level of CSE4/CENP-A at centromeres (PubMed:32079723). Decreases internucleosome spacing at protein-coding genes (PubMed:25406467). Decreases localization of RNA polymerase II to the histone HTA1-HTB1 gene locus during the G1/S transition (PubMed:22156209). Decreases HTA1 RNA level (PubMed:19683497). Heterochromatin spreading downstream of the silent mating-type locus HMR (PubMed:16079223). Decreases cell population growth; simultaneous disruption of proteins required for maintaining centromere and kinetochore function, including CLH4 and CBF1, enhances the growth defect (PubMed:32079723). Present with 172 molecules/cell in log phase SD medium. Belongs to the AAA ATPase family.