mediator complex (mediator of RNA polymerase 2 transcription)

Introduction

see redefined-classes.lisp

Function

• essential for basal & regulated expression of nearly all RNA polymerase 2-dependent genes
• can either repress or activate transcription
• may act as a bridge) (conveying regulatory information from enhancers & other control elements to the promoter
• serves as a scaffold for the assembly of a functional preinitiation complex with RNA polymerase 2 & the general transcription factors

Structure

• subunits:
  • MED1, MED4, MED6, MED7, MED8, MED9, MED10, MED11, MED12, MED13, MED13L, MED14, MED15, MED16, MED17, MED18, MED19, MED20, MED21, MED22, MED23, MED24, MED25, MED26, MED27, MED29, MED30, MED31, CCNC, CDK8 & CDC2L6/CDK11
• the MED12, MED13, CCNC & CDK8 subunits form a distinct module termed the CDK8 module
• mediator containing the CDK8 module is less active than mediator without in supporting transcriptional activation
• individual preparations of the mediator complex lacking one or more distinct subunits have been variously termed ARC, CRSP, DRIP, PC2, SMCC & TRAP

Notes

• it appears that several mediator complexes exist

More general terms

• molecular complex

More specific terms

• IXL mediator complex (mediator of RNA polymerase 2 transcription)
• MED8 mediator complex (mediator of RNA polymerase 2 transcription)
• SMCC mediator complex (mediator of RNA polymerase 2 transcription)