This Mediator complex subunit was formerly known as Srb4 in yeasts or Trap80 in Drosophila and human. The Med17 subunit is located within the head domain and is essential for cell viability to the extent that a mutant strain of cerevisiae lacking it shows all RNA polymerase II-dependent transcription ceasing at non-permissive temperatures.

1: 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

2: Analysis of Schizosaccharomyces pombe mediator reveals a set of essential subunits conserved between yeast and metazoan cells. Spahr H, Samuelsen CO, Baraznenok V, Ernest I, Huylebroeck D, Remacle JE, Samuelsson T, Kieselbach T, Holmberg S, Gustafsson CM; Proc Natl Acad Sci U S A 2001;98:11985-11990. PMID:11572939

3: The classical srb4-138 mutant allele causes dissociation of yeast Mediator. Linder T, Zhu X, Baraznenok V, Gustafsson CM; Biochem Biophys Res Commun. 2006;349:948-953. PMID:16962561