module: dmel_cyclin_k_cdk12_complex
title: Cyclin K-Cdk12 complex in Drosophila melanogaster
label: Cyclin K-Cdk12 complex
module_type: PROTEIN_COMPLEX
description: >-
  Cdk12 and its partner cyclin K form a transcription-associated kinase that
  phosphorylates the C-terminal domain of elongating RNA polymerase II. CDK12
  activity supports productive elongation and co-transcriptional processing,
  particularly of long genes. In Drosophila, Cdk12 has also been implicated in
  the control of transcription and chromatin silencing.
summary: >-
  Cyclin K-Cdk12 kinase that phosphorylates the RNA polymerase II C-terminal
  domain during elongation.
concepts:
  - {id: GO:0002944, label: cyclin K-CDK12 complex}
cellular_components:
  - {id: GO:0005634, label: nucleus}
group: CLNK-C12
roles:
  Cdk12: catalytic kinase subunit
  CycK: cyclin regulatory subunit
unit_functions:
  Cdk12: {id: GO:0008353, label: RNA polymerase II CTD heptapeptide repeat kinase activity}
  CycK: {id: GO:0016538, label: cyclin-dependent protein serine/threonine kinase regulator activity}
notes: >-
  Cyclin K also partners with Cdk13 in mammals; no Cdk13 complex is grouped by
  FlyBase.