The Med proteins of yeast and their function through the RNA polymerase II carboxy-terminal domain.
Mediator was resolved from yeast as a multiprotein complex on the basis of its requirement for transcriptional activation in a fully defined system. Three groups of mediator polypeptides could be distinguished: the products of five SRB genes, identified as suppressors of carboxy-terminal domain (CTD)-truncation mutants; products of four genes identified as global repressors; and six members of a new protein family, termed Med, thought to be primarily responsible for transcriptional activation. Notably absent from the purified mediator were Srbs 8, 9, 10, and 11, as well as members of the SWI/SNF complex. The CTD was required for function of mediator in vitro, in keeping with previous indications of involvement of the CTD in transcriptional activation in vivo. Evidence for human homologs of several mediator proteins, including Med7, points to similar mechanisms in higher cells.
Myers
L C
LC
Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5400, USA.
Gustafsson
C M
CM
Bushnell
D A
DA
Lui
M
M
Erdjument-Bromage
H
H
Tempst
P
P
Kornberg
R D
RD
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D018076:DNA, Complementary; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D056892:Mediator Complex; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes; D012319:RNA Polymerase II / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018076:DNA, Complementary; D005656:Fungal Proteins; C110184:MED7 protein, S cerevisiae; D046911:Macromolecular Substances; D056892:Mediator Complex; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D012319:RNA Polymerase II