FIGURE 1.

Comparison of hCDK12 to other CDKs. Schematics of CDK12, CDK9, and CDK2 primary structure, relative amino acid positions are indicated below each sequence with the kinase homology domain highlighted as an oval. Unlike most CDKs, CDK12 contains long N- and C-terminal arms that extend from the Ser/Thr kinase homology domain. These arms contain stretches of low complexity (LC) sequence (marked in red) and RS domains; motifs characteristic of splicing factors and believed to mediate protein-protein interactions.