Mediator complexes are basic necessities for linking transcriptional regulators to RNA polymerase II. This domain, Med1, is conserved from plants to fungi to humans and forms part of the Med9 submodule of the Srb/Med complex. it is one of three subunits essential for viability of the whole organism via its role in environmentally-directed cell-fate decisions [1]. Med1 is part of the tail region of the Mediator complex [2].

1: Evidence for a mediator of RNA polymerase II transcriptional regulation conserved from yeast to man. Boube M, Joulia L, Cribbs DL, Bourbon HM; Cell. 2002;110:143-151. PMID:12150923

2: A unified nomenclature for protein subunits of mediator complexes linking transcriptional regulators to RNA polymerase II. Bourbon HM, Aguilera A, Ansari AZ, Asturias FJ, Berk AJ, Bjorklund S, Blackwell TK, Borggrefe T, Carey M, Carlson M, Conaway JW, Conaway RC, Emmons SW, Fondell JD, Freedman LP, Fukasawa T, Gustafsson CM, Han M, He X, Herman PK, Hinnebusch AG, Holmberg S, Mol Cell. 2004;14:553-557. PMID:15175151