Non-histone component of centromeric chromatin; acts as a Cse4p specific chaperone that recognizes the centromere-targeting domain in the HFD of histone H3 variant, Cse4p, and recruits it to centromeres; involved in the assembly and maintenance of Cse4-H4 at centromeres; required for kinetochore assembly and G2/M progression; may protect Cse4p from ubiquitination; homolog of mammalian HJURP