The human CDK8 subcomplex is a histone kinase that requires Med12 for activity and can function independently of mediator.
Knuesel MT, Meyer KD, Donner AJ, Espinosa JM, Taatjes DJ. The human CDK8 subcomplex is a histone kinase that requires Med12 for activity and can function independently of mediator. Mol Cell Biol. 2009 Feb; 29(3):650-61.