because a 10 % increase in the h2a/dna ratio observed in interphase-mitosis transition explained the stoichiometric conversion of a24 to h2a , it appears that ubiquitin bound to h2a of nucleosomal surfaces in interphase is released at mitosis whereas the total h2a remains as a structural component of nucleosomes .
C0019646
h2a
C0028623
nucleosomes