Mediator Complex Subunit 20 (MED20)

MED20 is a subunit of the Mediator complex, a multiprotein coactivator of RNA transcription that interacts with DNA-bound transcriptional activators, RNA polymerase II , and general initiation factors.The deduced 209-amino acid protein shares 44% amino identity with Drosophila Trfp. TRFP had an apparent molecular mass of 28 kD by SDS-PAGE.Xiao et al. (1999) identified TRFP as a component of an RNA polymerase II-SRB complex. The TRFP-containing complex could substitute for core RNA polymerase II in driving basal transcription from a minimal promoter.By coexpression of epitope-tagged Mediator subunits, Sato et al. (2003) found that TRFP appeared to bridge an interaction between the Mediator subunits MED29 and p28b (MED18).