a protein kinase of the CDK family. Along with cyclin C forms part of the RNA polymerase II holoenzyme complex. Phosphorylates the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II. Regulates transcription by targeting the CDK7/cyclin H subunits of the general transcription initiation factor IIH (TFIIH), thus providing a link between the 'Mediator-like' protein complexes and the basal transcription machinery. Note: This description may include information from UniProtKB.
Protein type: Protein kinase, CMGC; EC 126.96.36.199; EC 188.8.131.52; Protein kinase, Ser/Thr (non-receptor); Kinase, protein; CMGC group; CDK family; CDK8 subfamily
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.