Required during anaphase to drive sister chromatid separation to promote flux by actively depolymerizing kinetochore microtubules at their pole-associated minus ends; thereby moving chromatids through a "poleward flux". {ECO:0000269|PubMed:14681690; ECO:0000269|PubMed:20946984; ECO:0000269|PubMed:24100293}.