CDK12 is a transcription elongation-associated CTD kinase, the metazoan ortholog of yeast Ctk1

B Bartkowiak, P Liu, H. P Phatnani, N. J Fuda, J. J Cooper, D. H Price, K Adelman, J. T Lis and A. L. Greenleaf

Genes & Development 24 ( 20 ): 2303 - 2316 , 2010