Mediator is a large complex of up to 33 proteins that is conserved from plants through fungi to humans - the number and representation of individual subunits varying with species [1-2]. It is arranged into four different sections, a core, a head, a tail and a kinase-activity part, and the number of subunits within each of these is what varies with species. Overall, Mediator regulates the transcriptional activity of RNA polymerase II but it would appear that each of the four different sections has a slightly different function. Med16 is one of the subunits of the Tail portion of the Mediator complex and is required for lipopolysaccharide gene-expression [4,5]. This entry represents the N-terminal beta-propeller domain [5].

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: A set of consensus mammalian mediator subunits identified by multidimensional protein identification technology. Sato S, Tomomori-Sato C, Parmely TJ, Florens L, Zybailov B, Swanson SK, Banks CA, Jin J, Cai Y, Washburn MP, Conaway JW, Conaway RC; Mol Cell. 2004;14:685-691. PMID:15175163

3: Structure-system correlation identifies a gene regulatory Mediator submodule. Lariviere L, Seizl M, van Wageningen S, Rother S, van de Pasch L, Feldmann H, Strasser K, Hahn S, Holstege FC, Cramer P; Genes Dev. 2008;22:872-877. PMID:18381891

4: MED16 and MED23 of Mediator are coactivators of lipopolysaccharide- and heat-shock-induced transcriptional activators. Kim TW, Kwon YJ, Kim JM, Song YH, Kim SN, Kim YJ; Proc Natl Acad Sci U S A. 2004;101:12153-12158. PMID:15297616

5: Structures of the human Mediator and Mediator-bound preinitiation complex. Chen X, Yin X, Li J, Wu Z, Qi Y, Wang X, Liu W, Xu Y; Science. 2021; [Epub ahead of print] PMID:33958484