| abstract |
first cyclin box found in cyclin-T (CCNT) family. The CCNT family includes two C-type cyclins, cyclin-T1 (CCNT1) and cyclin-T2 (CCNT2), both of which are regulatory subunits of the cyclin-dependent kinase pair (CDK9/cyclin-T) complex, also called positive transcription elongation factor B (P-TEFb), which is proposed to facilitate the transition from abortive to productive elongation by phosphorylating the CTD (C-terminal domain) of the large subunit of RNA polymerase II (RNA Pol II). Members of this family contain two cyclin boxes. This model corresponds to the first one. The cyclin box is a protein binding domain. |