UbcH10 is an essential mediator of mitotic destruction events and cell cycle progression. It catalyzes the destruction of cyclins A and B in conjunction with the anaphase-promoting complex. This activity is essential at the end of mitosis for the inactivation of their partner kinase Cdc2 and exit from mitosis into G1 of the next cell cycle. This enzyme has a mutation of the active site from cysteine to serine which abolishes the ability of UbcH10 to transfer ubiquitin to an accepting E3 protein. Ideal for use as a negative or competitive control, or to study protein-protein interactions.