The Mediator (MED) complex serves as a hub for transcriptional signaling events, bridging transcriptional activators and repressors. This large multi-protein complex has a central core conserved from yeast to humans. The core is composed of three modules: head, middle, and tail. A separate module, a Cdk8 kinase module called the CKM complex. (Adapted from
FBrf0226415 and
FBrf0191850).