Members of this family of viral cyclins adopt a helical structure consisting of five alpha-helices, with one helix surrounded by the others. They specifically activate CDK6 of host cells to a very high degree [1].
Cyclins regulate cyclin dependent kinases (CDKs). Swiss:P22674 is a Uracil-DNA glycosylase that is related to other cyclins [4]. Cyclins contain two domains of similar all-alpha fold, of which this family corresponds with the N-terminal domain.