| Type: | Domain | Name: | Cyclin domain, herpesvirus |
| Description: | Cyclins are eukaryotic proteins that play an active role in controlling nuclear cell division cycles [], and regulate cyclin dependent kinases (CDKs). Cyclins, together with the p34 (cdc2) or cdk2 kinases, form the Maturation Promoting Factor (MPF). There are two main groups of cyclins, G1/S cyclins, which are essential for the control of the cell cycle at the G1/S (start) transition, and G2/M cyclins, which are essential for the control of the cell cycle at the G2/M (mitosis) transition. G2/M cyclins accumulate steadily during G2 and are abruptly destroyed as cells exit from mitosis (at the end of the M-phase). In most species, there are multiple forms of G1 and G2 cyclins. For example, in vertebrates, there are two G2 cyclins, A and B, and at least three G1 cyclins, C, D, and E.Cyclin homologues have been found in various viruses, including Saimiriine herpesvirus 2(Herpesvirus saimiri) and Human herpesvirus 8(HHV-8) (Kaposi's sarcoma-associated herpesvirus). These viral homologues differ from their cellular counterparts in that the viral proteins have gained new functions and eliminated others to harness the cell and benefit the virus [].This entry represents a domain found in a family of viral cyclins that specifically activate CDK6 of host cells to a very high degree []. This domain adopts a helical structure consisting of five alpha-helices, with one helix surrounded by the others. | Short Name: | Cyclin_dom_herpesvir |
